diff mbox series

[v2] Pioneer devices: engage implicit feedback sync for playback

Message ID CAEsQvcs9LcciAYjoB64Kt_VaSww4EAW4-qN0ED5jDA0GeeTtDg@mail.gmail.com (mailing list archive)
State New, archived
Headers show
Series [v2] Pioneer devices: engage implicit feedback sync for playback | expand

Commit Message

Geraldo Nascimento April 5, 2021, 1:49 p.m. UTC
Dear Linux users of Pioneer gear, please disregard v1 of this patch and
test this instead if at all possible.

My initial assessment that we needed to let the capture EP be opened twice
was clearly proven wrong by further testing. This is good because if we
really needed that it would require a lot of reengineering inside ALSA.

One thing that still boggles my mind though is why we need a special
Pioneer case inside snd_usb_parse_implicit_fb_quirk that returns 1 like a
capture quirk was found.

This is a highly experimental patch on top of 5.12-rc6 that's supposed to
engage implicit feedback sync on the playback for Pioneer devices. Without
implicit feedback sync the inputs started glitching due to clock drift in
about an hour in my Pioneer DJ DDJ-SR2.

Once again I'd like to thank Takashi Iwai. He's the true author of the bulk
of this code, I just adapted it and coerced it into working.

Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>

 static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
                                     struct audioformat *fmt,
                                     int iface, int altset)
@@ -306,7 +307,7 @@ static int audioformat_implicit_fb_quirk
            alts->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
            (USB_ID_VENDOR(chip->usb_id) == 0x2b73 || /* Pioneer */
             USB_ID_VENDOR(chip->usb_id) == 0x08e4    /* Pioneer */)) {
-               if (skip_pioneer_sync_ep(chip, fmt, alts))
+               if (add_pioneer_implicit_fb(chip, fmt, alts))
                        return 1;
        }

@@ -339,8 +340,20 @@ int snd_usb_parse_implicit_fb_quirk(stru
                                    struct audioformat *fmt,
                                    struct usb_host_interface *alts)
 {
-       if (fmt->endpoint & USB_DIR_IN)
-               return audioformat_capture_quirk(chip, fmt, alts);
+        bool isPioneer;
+
+        if (alts->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
+            (USB_ID_VENDOR(chip->usb_id) == 0x2b73 || /* Pioneer */
+             USB_ID_VENDOR(chip->usb_id) == 0x08e4    /* Pioneer */))
+            isPioneer = true;
+
+       if (fmt->endpoint & USB_DIR_IN) {
+                if (isPioneer == true)
+                    return 1;
+                else
+                   return audioformat_capture_quirk(chip, fmt, alts);
+        }
+
        else
                return audioformat_implicit_fb_quirk(chip, fmt, alts);
 }

Comments

Geraldo Nascimento April 5, 2021, 2:16 p.m. UTC | #1
Dr. Iwai, here's the additional debugging information you asked for.

First dyndbg log is for successful engagement of implicit feedback sync on
the playback.
Second case I modified snd_usb_parse_implicit_fb_quirk to return 0 as it
would normally, unsuccessful.
Third is lsusb -v of Pioneer DJ DDJ-SR2.

I think I know now why we need to return 1 like a capture quirk was found
inside snd_usb_parse_implicit_fb_quirk: if we don't it triggers sync ep
code inside pcm.c

As always, thank you for your time.

---

[ 6397.520597] xhci_hcd 0000:00:14.0: Port change event, 3-1, id 1, portsc:
0xa0206e1
[ 6397.520619] xhci_hcd 0000:00:14.0: resume root hub
[ 6397.520647] xhci_hcd 0000:00:14.0: handle_port_status: starting port
polling.
[ 6397.520747] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x206e1,
return 0x10101
[ 6397.520950] xhci_hcd 0000:00:14.0: clear port1 connect change, portsc:
0x6e1
[ 6397.521111] xhci_hcd 0000:00:14.0: Get port status 3-2 read: 0x2a0,
return 0x100
[ 6397.521147] xhci_hcd 0000:00:14.0: Get port status 3-3 read: 0x2a0,
return 0x100
[ 6397.521179] xhci_hcd 0000:00:14.0: Get port status 3-4 read: 0x2a0,
return 0x100
[ 6397.626337] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x6e1,
return 0x101
[ 6397.626387] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.626432] xhci_hcd 0000:00:14.0: Adding 1 ep ctx, 1 now active.
[ 6397.626441] xhci_hcd 0000:00:14.0: Slot 5 output ctx = 0x13efdc000 (dma)
[ 6397.626447] xhci_hcd 0000:00:14.0: Slot 5 input ctx = 0x13ec75000 (dma)
[ 6397.626456] xhci_hcd 0000:00:14.0: Set slot id 5 dcbaa entry
00000000225b73b8 to 0x13efdc000
[ 6397.626515] xhci_hcd 0000:00:14.0: set port reset, actual port 3-1
status  = 0x791
[ 6397.629635] xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping port
polling.
[ 6397.681751] xhci_hcd 0000:00:14.0: Port change event, 3-1, id 1, portsc:
0x200e03
[ 6397.681768] xhci_hcd 0000:00:14.0: handle_port_status: starting port
polling.
[ 6397.693020] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x200e03,
return 0x100503
[ 6397.693084] xhci_hcd 0000:00:14.0: clear port1 reset change, portsc:
0xe03
[ 6397.719619] xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping port
polling.
[ 6397.749662] usb 3-1: new high-speed USB device number 6 using xhci_hcd
[ 6397.749689] xhci_hcd 0000:00:14.0: Set root hub portnum to 1
[ 6397.749697] xhci_hcd 0000:00:14.0: Set fake root hub portnum to 1
[ 6397.749702] xhci_hcd 0000:00:14.0: udev->tt = 0000000000000000
[ 6397.749709] xhci_hcd 0000:00:14.0: udev->ttport = 0x0
[ 6397.749720] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.749762] xhci_hcd 0000:00:14.0: Successful setup context command
[ 6397.749771] xhci_hcd 0000:00:14.0: Op regs DCBAA ptr = 0x00000236cef000
[ 6397.749778] xhci_hcd 0000:00:14.0: Slot ID 5 dcbaa entry
@00000000225b73b8 = 0x0000013efdc000
[ 6397.749787] xhci_hcd 0000:00:14.0: Output Context DMA address =
0x13efdc000
[ 6397.749792] xhci_hcd 0000:00:14.0: Internal device address = 0
[ 6397.749878] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6397.749925] xhci_hcd 0000:00:14.0: set port reset, actual port 3-1
status  = 0xf91
[ 6397.805146] xhci_hcd 0000:00:14.0: Port change event, 3-1, id 1, portsc:
0x200e03
[ 6397.805161] xhci_hcd 0000:00:14.0: handle_port_status: starting port
polling.
[ 6397.816340] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x200e03,
return 0x100503
[ 6397.816403] xhci_hcd 0000:00:14.0: clear port1 reset change, portsc:
0xe03
[ 6397.872940] xhci_hcd 0000:00:14.0: Resetting device with slot ID 5
[ 6397.872964] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.872979] xhci_hcd 0000:00:14.0: Completed reset device command.
[ 6397.872995] xhci_hcd 0000:00:14.0: Can't reset device (slot ID 5) in
default state
[ 6397.873001] xhci_hcd 0000:00:14.0: Not freeing device rings.
[ 6397.873013] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.873057] xhci_hcd 0000:00:14.0: Successful setup address command
[ 6397.873066] xhci_hcd 0000:00:14.0: Op regs DCBAA ptr = 0x00000236cef000
[ 6397.873073] xhci_hcd 0000:00:14.0: Slot ID 5 dcbaa entry
@00000000225b73b8 = 0x0000013efdc000
[ 6397.873083] xhci_hcd 0000:00:14.0: Output Context DMA address =
0x13efdc000
[ 6397.873088] xhci_hcd 0000:00:14.0: Internal device address = 5
[ 6397.890400] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6397.890503] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6397.890743] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6397.890817] usb 3-1: New USB device found, idVendor=2b73,
idProduct=001e, bcdDevice= 1.01
[ 6397.890828] usb 3-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 6397.890835] usb 3-1: Product: DDJ-SR2
[ 6397.890840] usb 3-1: Manufacturer: Pioneer DJ Corporation
[ 6397.891132] xhci_hcd 0000:00:14.0: add ep 0x85, slot id 5, new drop
flags = 0x0, new add flags = 0x800
[ 6397.891165] xhci_hcd 0000:00:14.0: add ep 0x4, slot id 5, new drop flags
= 0x0, new add flags = 0x900
[ 6397.891183] xhci_hcd 0000:00:14.0: add ep 0x87, slot id 5, new drop
flags = 0x0, new add flags = 0x8900
[ 6397.891196] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
00000000298860cb
[ 6397.891210] xhci_hcd 0000:00:14.0: Adding 3 ep ctxs, 4 now active.
[ 6397.891225] xhci_hcd 0000:00:14.0: Recalculating BW for rootport 1
[ 6397.891236] xhci_hcd 0000:00:14.0: Final bandwidth: 42, Limit: 1607,
Reserved: 322, Available: 77 percent
[ 6397.891253] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.891348] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command
[ 6397.891468] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.891493] xhci_hcd 0000:00:14.0: Stopped on No-op or Link TRB for slot
5 ep 10
[ 6397.891522] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.891609] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.891841] xhci_hcd 0000:00:14.0: Stopped on No-op or Link TRB for slot
5 ep 7
[ 6397.891856] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.891923] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.891949] xhci_hcd 0000:00:14.0: Stopped on No-op or Link TRB for slot
5 ep 14
[ 6397.891962] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6397.892364] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6397.892476] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6397.892543] usb 3-1: 0:1: added playback implicit_fb sync_ep 82, iface
0:1
[ 6397.892562] usb 3-1: Creating new data endpoint #1
[ 6397.892568] usb 3-1: Creating new data endpoint #82
[ 6397.892574] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
00000000298860cb
[ 6397.892683] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6397.892706] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
00000000298860cb
[ 6397.892771] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6397.969579] xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping port
polling.
[ 6402.946313] xhci_hcd 0000:00:14.0: Cancel URB 00000000c89bac54, dev 1,
ep 0x0, starting at offset 0x13ef91210
[ 6402.946353] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6402.946371] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 5 ep
0
[ 6402.946383] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13ef91210 (dma).
[ 6402.946392] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x13ef91230, cycle 1
[ 6402.946398] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6402.946409] xhci_hcd 0000:00:14.0: Successful Set TR Deq Ptr cmd, deq =
@13ef91230
[ 6402.946417] xhci_hcd 0000:00:14.0: Giveback URB 00000000c89bac54, len =
0, expected = 0, status = -115
[ 6402.947692] hid-generic 0003:2B73:001E.0005: hiddev96,hidraw0: USB HID
v1.11 Device [Pioneer DJ Corporation DDJ-SR2] on usb-0000:00:14.0-1/input3
[ 6424.552616] usb 3-1: Open EP 0x82, iface=0:1, idx=1
[ 6424.552626] usb 3-1:   channels=6, rate=44100, format=S24_3LE,
period_bytes=9216, periods=2, implicit_fb=0
[ 6424.552632] usb 3-1: Setting usb interface 0:0 for EP 0x82
[ 6424.552638] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
00000000298860cb
[ 6424.552715] usb 3-1: Setting usb interface 0:1 for EP 0x82
[ 6424.552725] xhci_hcd 0000:00:14.0: add ep 0x1, slot id 5, new drop flags
= 0x0, new add flags = 0x5
[ 6424.552732] xhci_hcd 0000:00:14.0: add ep 0x82, slot id 5, new drop
flags = 0x0, new add flags = 0x25
[ 6424.552736] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
00000000298860cb
[ 6424.552741] xhci_hcd 0000:00:14.0: Adding 2 ep ctxs, 6 now active.
[ 6424.552746] xhci_hcd 0000:00:14.0: Recalculating BW for rootport 1
[ 6424.552750] xhci_hcd 0000:00:14.0: Final bandwidth: 282, Limit: 1607,
Reserved: 322, Available: 62 percent
[ 6424.552757] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6424.552811] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command
[ 6424.552983] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6424.553011] usb 3-1: Setting params for data EP 0x82, pipe 0x10680
[ 6424.553021] usb 3-1: Set up 12 URBS, ret=0
[ 6424.553113] usb 3-1: Open EP 0x1, iface=0:1, idx=0
[ 6424.553117] usb 3-1:   channels=4, rate=44100, format=S24_3LE,
period_bytes=6144, periods=2, implicit_fb=1
[ 6424.553122] usb 3-1: Reopened EP 0x82 (count 1)
[ 6424.553126] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6424.553129] usb 3-1: Setting params for data EP 0x1, pipe 0x8600
[ 6424.553138] usb 3-1: Set up 12 URBS, ret=0
[ 6424.553163] usb 3-1: Starting data EP 0x1 (running 0)
[ 6424.553168] usb 3-1: No URB submission due to implicit fb sync
[ 6424.553170] usb 3-1: Starting data EP 0x82 (running 0)
[ 6424.553219] usb 3-1: 12 URBs submitted for EP 0x82
[ 6424.555173] usb 3-1: Starting data EP 0x82 (running 1)
[ 6424.555180] usb 3-1: 0:1 Start Capture PCM
[ 6424.555184] usb 3-1: 0:1 Start Playback PCM


---

[ 6518.662829] xhci_hcd 0000:00:14.0: resume root hub
[ 6518.662849] xhci_hcd 0000:00:14.0: handle_port_status: starting port
polling.
[ 6518.663623] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x206e1,
return 0x10101
[ 6518.663703] xhci_hcd 0000:00:14.0: clear port1 connect change, portsc:
0x6e1
[ 6518.663728] xhci_hcd 0000:00:14.0: Get port status 3-2 read: 0x2a0,
return 0x100
[ 6518.663750] xhci_hcd 0000:00:14.0: Get port status 3-3 read: 0x2a0,
return 0x100
[ 6518.663769] xhci_hcd 0000:00:14.0: Get port status 3-4 read: 0x2a0,
return 0x100
[ 6518.719588] xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping port
polling.
[ 6518.769612] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x6e1,
return 0x101
[ 6518.769668] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6518.769712] xhci_hcd 0000:00:14.0: Adding 1 ep ctx, 1 now active.
[ 6518.769725] xhci_hcd 0000:00:14.0: Slot 6 output ctx = 0x13efdc000 (dma)
[ 6518.769734] xhci_hcd 0000:00:14.0: Slot 6 input ctx = 0x13ec75000 (dma)
[ 6518.769744] xhci_hcd 0000:00:14.0: Set slot id 6 dcbaa entry
00000000d24104f6 to 0x13efdc000
[ 6518.769816] xhci_hcd 0000:00:14.0: set port reset, actual port 3-1
status  = 0x791
[ 6518.772897] xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping port
polling.
[ 6518.824991] xhci_hcd 0000:00:14.0: Port change event, 3-1, id 1, portsc:
0x200e03
[ 6518.825012] xhci_hcd 0000:00:14.0: handle_port_status: starting port
polling.
[ 6518.836254] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x200e03,
return 0x100503
[ 6518.836306] xhci_hcd 0000:00:14.0: clear port1 reset change, portsc:
0xe03
[ 6518.892917] usb 3-1: new high-speed USB device number 7 using xhci_hcd
[ 6518.892938] xhci_hcd 0000:00:14.0: Set root hub portnum to 1
[ 6518.892945] xhci_hcd 0000:00:14.0: Set fake root hub portnum to 1
[ 6518.892950] xhci_hcd 0000:00:14.0: udev->tt = 0000000000000000
[ 6518.892956] xhci_hcd 0000:00:14.0: udev->ttport = 0x0
[ 6518.892966] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6518.892999] xhci_hcd 0000:00:14.0: Successful setup context command
[ 6518.893008] xhci_hcd 0000:00:14.0: Op regs DCBAA ptr = 0x00000236cef000
[ 6518.893015] xhci_hcd 0000:00:14.0: Slot ID 6 dcbaa entry
@00000000d24104f6 = 0x0000013efdc000
[ 6518.893023] xhci_hcd 0000:00:14.0: Output Context DMA address =
0x13efdc000
[ 6518.893029] xhci_hcd 0000:00:14.0: Internal device address = 0
[ 6518.893208] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6518.893287] xhci_hcd 0000:00:14.0: set port reset, actual port 3-1
status  = 0xf91
[ 6518.948510] xhci_hcd 0000:00:14.0: Port change event, 3-1, id 1, portsc:
0x200e03
[ 6518.948533] xhci_hcd 0000:00:14.0: handle_port_status: starting port
polling.
[ 6518.959642] xhci_hcd 0000:00:14.0: Get port status 3-1 read: 0x200e03,
return 0x100503
[ 6518.959704] xhci_hcd 0000:00:14.0: clear port1 reset change, portsc:
0xe03
[ 6518.969594] xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping port
polling.
[ 6519.016304] xhci_hcd 0000:00:14.0: Resetting device with slot ID 6
[ 6519.016330] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.016351] xhci_hcd 0000:00:14.0: Completed reset device command.
[ 6519.016370] xhci_hcd 0000:00:14.0: Can't reset device (slot ID 6) in
default state
[ 6519.016377] xhci_hcd 0000:00:14.0: Not freeing device rings.
[ 6519.016390] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.016437] xhci_hcd 0000:00:14.0: Successful setup address command
[ 6519.016446] xhci_hcd 0000:00:14.0: Op regs DCBAA ptr = 0x00000236cef000
[ 6519.016454] xhci_hcd 0000:00:14.0: Slot ID 6 dcbaa entry
@00000000d24104f6 = 0x0000013efdc000
[ 6519.016463] xhci_hcd 0000:00:14.0: Output Context DMA address =
0x13efdc000
[ 6519.016469] xhci_hcd 0000:00:14.0: Internal device address = 6
[ 6519.033886] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6519.034170] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6519.034352] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6519.034416] usb 3-1: New USB device found, idVendor=2b73,
idProduct=001e, bcdDevice= 1.01
[ 6519.034427] usb 3-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 6519.034435] usb 3-1: Product: DDJ-SR2
[ 6519.034440] usb 3-1: Manufacturer: Pioneer DJ Corporation
[ 6519.034757] xhci_hcd 0000:00:14.0: add ep 0x85, slot id 6, new drop
flags = 0x0, new add flags = 0x800
[ 6519.034776] xhci_hcd 0000:00:14.0: add ep 0x4, slot id 6, new drop flags
= 0x0, new add flags = 0x900
[ 6519.034790] xhci_hcd 0000:00:14.0: add ep 0x87, slot id 6, new drop
flags = 0x0, new add flags = 0x8900
[ 6519.034799] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
0000000041e6ad6d
[ 6519.034811] xhci_hcd 0000:00:14.0: Adding 3 ep ctxs, 4 now active.
[ 6519.034821] xhci_hcd 0000:00:14.0: Recalculating BW for rootport 1
[ 6519.034828] xhci_hcd 0000:00:14.0: Final bandwidth: 42, Limit: 1607,
Reserved: 322, Available: 77 percent
[ 6519.034842] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.045845] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command
[ 6519.045948] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.045982] xhci_hcd 0000:00:14.0: Stopped on No-op or Link TRB for slot
6 ep 10
[ 6519.046008] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.046083] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.046107] xhci_hcd 0000:00:14.0: Stopped on No-op or Link TRB for slot
6 ep 7
[ 6519.046123] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.046239] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6519.046528] xhci_hcd 0000:00:14.0: Stopped on No-op or Link TRB for slot
6 ep 14
[ 6519.046813] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6524.122938] xhci_hcd 0000:00:14.0: Cancel URB 000000005dc311b3, dev 1,
ep 0x0, starting at offset 0x13ef91170
[ 6524.122971] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6524.122989] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 6 ep
0
[ 6524.123001] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13ef91170 (dma).
[ 6524.123010] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x13ef91190, cycle 1
[ 6524.123016] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6524.123028] xhci_hcd 0000:00:14.0: Successful Set TR Deq Ptr cmd, deq =
@13ef91190
[ 6524.123036] xhci_hcd 0000:00:14.0: Giveback URB 000000005dc311b3, len =
0, expected = 0, status = -115
[ 6524.124748] hid-generic 0003:2B73:001E.0006: hiddev96,hidraw0: USB HID
v1.11 Device [Pioneer DJ Corporation DDJ-SR2] on usb-0000:00:14.0-1/input3
[ 6524.140705] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6524.140856] xhci_hcd 0000:00:14.0: Waiting for status stage event
[ 6524.140936] usb 3-1: 0:1: added playback implicit_fb sync_ep 82, iface
0:1
[ 6524.140951] usb 3-1: Creating new data endpoint #1
[ 6524.140954] usb 3-1: Creating new data endpoint #82
[ 6524.140958] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
0000000041e6ad6d
[ 6524.141095] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6524.141110] usb 3-1: 0:1: found sync_ep=0x82, iface=0, alt=1,
implicit_fb=0
[ 6524.141118] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
0000000041e6ad6d
[ 6524.141274] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6524.141683] usbcore: registered new interface driver snd-usb-audio
[ 6530.912038] usb 3-1: Open EP 0x82, iface=0:1, idx=1
[ 6530.912047] usb 3-1:   channels=6, rate=44100, format=S24_3LE,
period_bytes=9216, periods=2, implicit_fb=0
[ 6530.912052] usb 3-1: Reopened EP 0x82 (count 1)
[ 6530.912056] usb 3-1: Setting usb interface 0:0 for EP 0x82
[ 6530.912062] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
0000000041e6ad6d
[ 6530.912125] usb 3-1: Setting usb interface 0:1 for EP 0x82
[ 6530.912134] xhci_hcd 0000:00:14.0: add ep 0x1, slot id 6, new drop flags
= 0x0, new add flags = 0x5
[ 6530.912141] xhci_hcd 0000:00:14.0: add ep 0x82, slot id 6, new drop
flags = 0x0, new add flags = 0x25
[ 6530.912146] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
0000000041e6ad6d
[ 6530.912151] xhci_hcd 0000:00:14.0: Adding 2 ep ctxs, 6 now active.
[ 6530.912156] xhci_hcd 0000:00:14.0: Recalculating BW for rootport 1
[ 6530.912160] xhci_hcd 0000:00:14.0: Final bandwidth: 282, Limit: 1607,
Reserved: 322, Available: 62 percent
[ 6530.912165] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6530.912221] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command
[ 6530.912412] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6530.912419] usb 3-1: Setting params for data EP 0x82, pipe 0x10780
[ 6530.912428] usb 3-1: Set up 12 URBS, ret=0
[ 6530.912525] usb 3-1: Open EP 0x1, iface=0:1, idx=0
[ 6530.912530] usb 3-1:   channels=4, rate=44100, format=S24_3LE,
period_bytes=6144, periods=2, implicit_fb=1
[ 6530.912535] usb 3-1: Reopened EP 0x82 (count 2)
[ 6530.912538] usb 3-1: 0:1 Set sample rate 44100, clock 0
[ 6530.912542] usb 3-1: Setting params for data EP 0x1, pipe 0x8700
[ 6530.912549] usb 3-1: Set up 12 URBS, ret=0
[ 6530.912575] usb 3-1: Starting data EP 0x1 (running 0)
[ 6530.912579] usb 3-1: No URB submission due to implicit fb sync
[ 6530.912582] usb 3-1: Starting data EP 0x82 (running 0)
[ 6530.912623] usb 3-1: 12 URBs submitted for EP 0x82
[ 6530.915746] usb 3-1: Starting data EP 0x82 (running 1)
[ 6530.915760] usb 3-1: Starting data EP 0x82 (running 2)
[ 6530.915766] usb 3-1: 0:1 Start Capture PCM
[ 6530.915772] usb 3-1: 0:1 Start Playback PCM
[ 6548.340701] usb 3-1: Stopping data EP 0x82 (running 3)
[ 6548.340709] usb 3-1: Stopping data EP 0x82 (running 2)
[ 6548.340713] usb 3-1: 0:1 Stop Capture PCM
[ 6548.340717] usb 3-1: Stopping data EP 0x82 (running 1)
[ 6548.340724] xhci_hcd 0000:00:14.0: Cancel URB 0000000017eaed8f, dev 1,
ep 0x82, starting at offset 0x13eef0b40
[ 6548.340731] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6548.340735] xhci_hcd 0000:00:14.0: Cancel URB 00000000d1c36d1d, dev 1,
ep 0x82, starting at offset 0x13eef0b50
[ 6548.340741] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 6 ep
4
[ 6548.340746] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b40 (dma).
[ 6548.340750] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b50 (dma).
[ 6548.340758] xhci_hcd 0000:00:14.0: Cancel URB 000000007dcb7021, dev 1,
ep 0x82, starting at offset 0x13eef0b60
[ 6548.340762] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6548.340766] xhci_hcd 0000:00:14.0: Cancel URB 00000000b381540e, dev 1,
ep 0x82, starting at offset 0x13eef0b70
[ 6548.340769] xhci_hcd 0000:00:14.0: Cancel URB 00000000059964b3, dev 1,
ep 0x82, starting at offset 0x13eef0b80
[ 6548.340773] xhci_hcd 0000:00:14.0: Cancel URB 0000000009d6cac7, dev 1,
ep 0x82, starting at offset 0x13eef0b90
[ 6548.340777] xhci_hcd 0000:00:14.0: Cancel URB 000000008fc1dbd6, dev 1,
ep 0x82, starting at offset 0x13eef0ba0
[ 6548.340783] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 6 ep
4
[ 6548.340786] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b60 (dma).
[ 6548.340789] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b70 (dma).
[ 6548.340792] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b80 (dma).
[ 6548.340795] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b90 (dma).
[ 6548.340798] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0ba0 (dma).
[ 6548.340806] xhci_hcd 0000:00:14.0: Cancel URB 00000000dd5ca99e, dev 1,
ep 0x82, starting at offset 0x13eef0bb0
[ 6548.340810] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6548.340814] xhci_hcd 0000:00:14.0: Cancel URB 000000003c889fa7, dev 1,
ep 0x82, starting at offset 0x13eef0bc0
[ 6548.340818] xhci_hcd 0000:00:14.0: Cancel URB 000000005c402de4, dev 1,
ep 0x82, starting at offset 0x13eef0b10
[ 6548.340823] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 6 ep
4
[ 6548.340826] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0bb0 (dma).
[ 6548.340829] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0bc0 (dma).
[ 6548.340832] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b10 (dma).
[ 6548.340836] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x13eef0b20, cycle 1
[ 6548.340839] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6548.340848] xhci_hcd 0000:00:14.0: Cancel URB 0000000012679da4, dev 1,
ep 0x82, starting at offset 0x13eef0b20
[ 6548.340851] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6548.340855] xhci_hcd 0000:00:14.0: Cancel URB 00000000353acb81, dev 1,
ep 0x82, starting at offset 0x13eef0b30
[ 6548.340860] usb 3-1: Stopping data EP 0x1 (running 1)
[ 6548.340861] xhci_hcd 0000:00:14.0: Successful Set TR Deq Ptr cmd, deq =
@13eef0b20
[ 6548.340864] usb 3-1: 0:1 Stop Playback PCM
[ 6548.340866] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b20 (dma).
[ 6548.340869] xhci_hcd 0000:00:14.0: Removing canceled TD starting at
0x13eef0b30 (dma).
[ 6548.340872] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x13eef0b30, cycle 1
[ 6548.340875] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6548.340901] xhci_hcd 0000:00:14.0: Successful Set TR Deq Ptr cmd, deq =
@13eef0b30
[ 6548.350377] usb 3-1: Closing EP 0x82 (count 3)
[ 6548.350384] usb 3-1: Closing EP 0x82 (count 2)
[ 6548.350396] usb 3-1: Closing EP 0x1 (count 1)
[ 6548.350398] usb 3-1: EP 0x1 closed
[ 6548.350400] usb 3-1: Closing EP 0x82 (count 1)
[ 6548.350401] usb 3-1: Setting usb interface 0:0 for EP 0x82
[ 6548.350406] xhci_hcd 0000:00:14.0: xhci_drop_endpoint called for udev
0000000041e6ad6d
[ 6548.350423] xhci_hcd 0000:00:14.0: drop ep 0x1, slot id 6, new drop
flags = 0x4, new add flags = 0x0
[ 6548.350426] xhci_hcd 0000:00:14.0: xhci_drop_endpoint called for udev
0000000041e6ad6d
[ 6548.350435] xhci_hcd 0000:00:14.0: drop ep 0x82, slot id 6, new drop
flags = 0x24, new add flags = 0x0
[ 6548.350438] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev
0000000041e6ad6d
[ 6548.350442] xhci_hcd 0000:00:14.0: Adding 0 ep ctxs, 6 now active.
[ 6548.350445] xhci_hcd 0000:00:14.0: Recalculating BW for rootport 1
[ 6548.350447] xhci_hcd 0000:00:14.0: Final bandwidth: 42, Limit: 1607,
Reserved: 322, Available: 77 percent
[ 6548.350451] xhci_hcd 0000:00:14.0: // Ding dong!
[ 6548.350509] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command
[ 6548.350512] xhci_hcd 0000:00:14.0: Removing 2 dropped ep ctxs, 4 now
active.
[ 6548.350644] usb 3-1: EP 0x82 closed

---

Bus 003 Device 007: ID 2b73:001e Pioneer DJ Corporation DDJ-SR2
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x2b73
  idProduct          0x001e
  bcdDevice            1.01
  iManufacturer           1 Pioneer DJ Corporation
  iProduct                2 DDJ-SR2
  iSerial                 0
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x00a2
    bNumInterfaces          4
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xc0
      Self Powered
    MaxPower                0mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       1
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0400  1x 1024 bytes
        bInterval               3
        bRefresh                0
        bSynchAddress           0
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0400  1x 1024 bytes
        bInterval               3
        bRefresh                0
        bSynchAddress           0
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      1 Control Device
      bInterfaceProtocol      0
      iInterface              0
      AudioControl Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      1 (HEADER)
        bcdADC               1.00
        wTotalLength       0x0009
        bInCollection           1
        baInterfaceNr(0)        2
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         1 Audio
      bInterfaceSubClass      3 MIDI Streaming
      bInterfaceProtocol      0
      iInterface              0
      MIDIStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (HEADER)
        bcdADC               1.00
        wTotalLength       0x0041
      MIDIStreaming Interface Descriptor:
        bLength                 6
        bDescriptorType        36
        bDescriptorSubtype      2 (MIDI_IN_JACK)
        bJackType               1 Embedded
        bJackID                 3
        iJack                   0
      MIDIStreaming Interface Descriptor:
        bLength                 6
        bDescriptorType        36
        bDescriptorSubtype      2 (MIDI_IN_JACK)
        bJackType               2 External
        bJackID                 1
        iJack                   0
      MIDIStreaming Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      3 (MIDI_OUT_JACK)
        bJackType               2 External
        bJackID                 4
        bNrInputPins            1
        baSourceID( 0)          3
        BaSourcePin( 0)         1
        iJack                   0
      MIDIStreaming Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      3 (MIDI_OUT_JACK)
        bJackType               1 Embedded
        bJackID                 2
        bNrInputPins            1
        baSourceID( 0)          1
        BaSourcePin( 0)         1
        iJack                   0
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
        bRefresh                0
        bSynchAddress           0
        MIDIStreaming Endpoint Descriptor:
          bLength                 5
          bDescriptorType        37
          bDescriptorSubtype      1 (GENERAL)
          bNumEmbMIDIJack         1
          baAssocJackID( 0)       2
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
        bRefresh                0
        bSynchAddress           0
        MIDIStreaming Endpoint Descriptor:
          bLength                 5
          bDescriptorType        37
          bDescriptorSubtype      1 (GENERAL)
          bNumEmbMIDIJack         1
          baAssocJackID( 0)       3
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.11
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      52
         Report Descriptors:
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x87  EP 7 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               4
can't get debug descriptor: Resource temporarily unavailable
Device Status:     0x0001
  Self Powered
Takashi Iwai April 6, 2021, 11:48 a.m. UTC | #2
On Mon, 05 Apr 2021 15:49:20 +0200,
Geraldo wrote:
> 
> Dear Linux users of Pioneer gear, please disregard v1 of this patch and test
> this instead if at all possible.
> 
> My initial assessment that we needed to let the capture EP be opened twice was
> clearly proven wrong by further testing. This is good because if we really
> needed that it would require a lot of reengineering inside ALSA.
> 
> One thing that still boggles my mind though is why we need a special Pioneer
> case inside snd_usb_parse_implicit_fb_quirk that returns 1 like a capture
> quirk was found.
> 
> This is a highly experimental patch on top of 5.12-rc6 that's supposed to
> engage implicit feedback sync on the playback for Pioneer devices. Without
> implicit feedback sync the inputs started glitching due to clock drift in
> about an hour in my Pioneer DJ DDJ-SR2.
> 
> Once again I'd like to thank Takashi Iwai. He's the true author of the bulk of
> this code, I just adapted it and coerced it into working.
> 
> Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>

Thanks for the patch!

It's interesting that Pioneer devices would actually work with the
implicit feedback mode.  It seems that the key point is to skip the
capture side; IIRC, we checked applying the quirk to the playback
side, but this wasn't enough or not properly working on some devices.

If that's the case, I believe a patch like below would be safer and
more inconsistent: it checks the device from both playback and capture
quirks with the same helper function.

Could you check whether this one works?   (It's totally untested.)


thanks,

Takashi

---
--- a/sound/usb/implicit.c
+++ b/sound/usb/implicit.c
@@ -167,18 +167,27 @@ static int add_roland_implicit_fb(struct snd_usb_audio *chip,
 				       ifnum, alts);
 }
 
-/* Playback and capture EPs on Pioneer devices share the same iface/altset,
- * but they don't seem working with the implicit fb mode well, hence we
- * just return as if the sync were already set up.
+/* Playback and capture EPs on Pioneer devices share the same iface/altset
+ * for the implicit feedback operation
  */
-static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
-				struct audioformat *fmt,
-				struct usb_host_interface *alts)
+static bool is_pioneer_implicit_fb(struct snd_usb_audio *chip,
+				   struct usb_host_interface *alts)
+
 {
 	struct usb_endpoint_descriptor *epd;
 
+	if (USB_ID_VENDOR(chip->usb_id) != 0x2b73 &&
+	    USB_ID_VENDOR(chip->usb_id) != 0x08e4)
+		return false;
+	if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
+		return false;
 	if (alts->desc.bNumEndpoints != 2)
-		return 0;
+		return false;
+
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_out(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return false;
 
 	epd = get_endpoint(alts, 1);
 	if (!usb_endpoint_is_isoc_in(epd) ||
@@ -187,8 +196,9 @@ static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
 	     USB_ENDPOINT_USAGE_DATA &&
 	     (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
 	     USB_ENDPOINT_USAGE_IMPLICIT_FB))
-		return 0;
-	return 1; /* don't handle with the implicit fb, just skip sync EP */
+		return false;
+
+	return true;
 }
 
 static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
@@ -297,13 +307,11 @@ static int audioformat_implicit_fb_quirk(struct snd_usb_audio *chip,
 	}
 
 	/* Pioneer devices with vendor spec class */
-	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
-	    alts->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
-	    (USB_ID_VENDOR(chip->usb_id) == 0x2b73 || /* Pioneer */
-	     USB_ID_VENDOR(chip->usb_id) == 0x08e4    /* Pioneer */)) {
-		if (skip_pioneer_sync_ep(chip, fmt, alts))
-			return 1;
-	}
+	if (is_pioneer_implicit_fb(chip, alts))
+		return add_implicit_fb_sync_ep(chip, fmt,
+					       get_endpoint(alts, 1)->bEndpointAddress,
+					       1, alts->desc.bInterfaceNumber,
+					       alts);
 
 	/* Try the generic implicit fb if available */
 	if (chip->generic_implicit_fb)
@@ -324,6 +332,8 @@ static int audioformat_capture_quirk(struct snd_usb_audio *chip,
 	if (p && p->type == IMPLICIT_FB_FIXED)
 		return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
 					       p->iface, NULL);
+	if (is_pioneer_implicit_fb(chip, alts))
+		return 1; /* skip */
 	return 0;
 }
Geraldo Nascimento April 6, 2021, 1:44 p.m. UTC | #3
Works for me Dr. Iwai, thank you!

Much more better styled now, and less hacky.

-Geraldo

Em Ter, 6 de abr de 2021 08:48, Takashi Iwai <tiwai@suse.de> escreveu:

> On Mon, 05 Apr 2021 15:49:20 +0200,
> Geraldo wrote:
> >
> > Dear Linux users of Pioneer gear, please disregard v1 of this patch and
> test
> > this instead if at all possible.
> >
> > My initial assessment that we needed to let the capture EP be opened
> twice was
> > clearly proven wrong by further testing. This is good because if we
> really
> > needed that it would require a lot of reengineering inside ALSA.
> >
> > One thing that still boggles my mind though is why we need a special
> Pioneer
> > case inside snd_usb_parse_implicit_fb_quirk that returns 1 like a capture
> > quirk was found.
> >
> > This is a highly experimental patch on top of 5.12-rc6 that's supposed to
> > engage implicit feedback sync on the playback for Pioneer devices.
> Without
> > implicit feedback sync the inputs started glitching due to clock drift in
> > about an hour in my Pioneer DJ DDJ-SR2.
> >
> > Once again I'd like to thank Takashi Iwai. He's the true author of the
> bulk of
> > this code, I just adapted it and coerced it into working.
> >
> > Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
>
> Thanks for the patch!
>
> It's interesting that Pioneer devices would actually work with the
> implicit feedback mode.  It seems that the key point is to skip the
> capture side; IIRC, we checked applying the quirk to the playback
> side, but this wasn't enough or not properly working on some devices.
>
> If that's the case, I believe a patch like below would be safer and
> more inconsistent: it checks the device from both playback and capture
> quirks with the same helper function.
>
> Could you check whether this one works?   (It's totally untested.)
>
>
> thanks,
>
> Takashi
>
> ---
> --- a/sound/usb/implicit.c
> +++ b/sound/usb/implicit.c
> @@ -167,18 +167,27 @@ static int add_roland_implicit_fb(struct
> snd_usb_audio *chip,
>                                        ifnum, alts);
>  }
>
> -/* Playback and capture EPs on Pioneer devices share the same
> iface/altset,
> - * but they don't seem working with the implicit fb mode well, hence we
> - * just return as if the sync were already set up.
> +/* Playback and capture EPs on Pioneer devices share the same iface/altset
> + * for the implicit feedback operation
>   */
> -static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
> -                               struct audioformat *fmt,
> -                               struct usb_host_interface *alts)
> +static bool is_pioneer_implicit_fb(struct snd_usb_audio *chip,
> +                                  struct usb_host_interface *alts)
> +
>  {
>         struct usb_endpoint_descriptor *epd;
>
> +       if (USB_ID_VENDOR(chip->usb_id) != 0x2b73 &&
> +           USB_ID_VENDOR(chip->usb_id) != 0x08e4)
> +               return false;
> +       if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
> +               return false;
>         if (alts->desc.bNumEndpoints != 2)
> -               return 0;
> +               return false;
> +
> +       epd = get_endpoint(alts, 0);
> +       if (!usb_endpoint_is_isoc_out(epd) ||
> +           (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) !=
> USB_ENDPOINT_SYNC_ASYNC)
> +               return false;
>
>         epd = get_endpoint(alts, 1);
>         if (!usb_endpoint_is_isoc_in(epd) ||
> @@ -187,8 +196,9 @@ static int skip_pioneer_sync_ep(struct snd_usb_audio
> *chip,
>              USB_ENDPOINT_USAGE_DATA &&
>              (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
>              USB_ENDPOINT_USAGE_IMPLICIT_FB))
> -               return 0;
> -       return 1; /* don't handle with the implicit fb, just skip sync EP
> */
> +               return false;
> +
> +       return true;
>  }
>
>  static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
> @@ -297,13 +307,11 @@ static int audioformat_implicit_fb_quirk(struct
> snd_usb_audio *chip,
>         }
>
>         /* Pioneer devices with vendor spec class */
> -       if (attr == USB_ENDPOINT_SYNC_ASYNC &&
> -           alts->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
> -           (USB_ID_VENDOR(chip->usb_id) == 0x2b73 || /* Pioneer */
> -            USB_ID_VENDOR(chip->usb_id) == 0x08e4    /* Pioneer */)) {
> -               if (skip_pioneer_sync_ep(chip, fmt, alts))
> -                       return 1;
> -       }
> +       if (is_pioneer_implicit_fb(chip, alts))
> +               return add_implicit_fb_sync_ep(chip, fmt,
> +                                              get_endpoint(alts,
> 1)->bEndpointAddress,
> +                                              1,
> alts->desc.bInterfaceNumber,
> +                                              alts);
>
>         /* Try the generic implicit fb if available */
>         if (chip->generic_implicit_fb)
> @@ -324,6 +332,8 @@ static int audioformat_capture_quirk(struct
> snd_usb_audio *chip,
>         if (p && p->type == IMPLICIT_FB_FIXED)
>                 return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
>                                                p->iface, NULL);
> +       if (is_pioneer_implicit_fb(chip, alts))
> +               return 1; /* skip */
>         return 0;
>  }
>
>
>
Olivia Mackintosh April 9, 2021, 11:07 a.m. UTC | #4
On Mon, Apr 05, 2021 at 10:49:20AM -0300, Geraldo wrote:
> Dear Linux users of Pioneer gear, please disregard v1 of this patch and
> test this instead if at all possible.
> 
> My initial assessment that we needed to let the capture EP be opened twice
> was clearly proven wrong by further testing. This is good because if we
> really needed that it would require a lot of reengineering inside ALSA.
> 
> One thing that still boggles my mind though is why we need a special
> Pioneer case inside snd_usb_parse_implicit_fb_quirk that returns 1 like a
> capture quirk was found.
> 
> This is a highly experimental patch on top of 5.12-rc6 that's supposed to
> engage implicit feedback sync on the playback for Pioneer devices. Without
> implicit feedback sync the inputs started glitching due to clock drift in
> about an hour in my Pioneer DJ DDJ-SR2.
> 
> Once again I'd like to thank Takashi Iwai. He's the true author of the bulk
> of this code, I just adapted it and coerced it into working.
> 
> Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>

Thank you Geraldo and Takashi for working on this patch. I'm currently
in the process of testing with the DJM-750 but it currently does not
work as expected. I'll debug futher and report back but would like to
make you aware of this in the meantime. It may not be a a fundamental
issue with the patch, but rather something incidental.

Kind regards,
Olivia
Geraldo Nascimento April 9, 2021, 5:31 p.m. UTC | #5
Hi, Olivia, thank you, glad you catched this and are able to test and debug
it. Let me know if I can be of any assistance.

Em Sex, 9 de abr de 2021 08:09, Olivia Mackintosh <livvy@base.nu> escreveu:

> On Mon, Apr 05, 2021 at 10:49:20AM -0300, Geraldo wrote:
> > Dear Linux users of Pioneer gear, please disregard v1 of this patch and
> > test this instead if at all possible.
> >
> > My initial assessment that we needed to let the capture EP be opened
> twice
> > was clearly proven wrong by further testing. This is good because if we
> > really needed that it would require a lot of reengineering inside ALSA.
> >
> > One thing that still boggles my mind though is why we need a special
> > Pioneer case inside snd_usb_parse_implicit_fb_quirk that returns 1 like a
> > capture quirk was found.
> >
> > This is a highly experimental patch on top of 5.12-rc6 that's supposed to
> > engage implicit feedback sync on the playback for Pioneer devices.
> Without
> > implicit feedback sync the inputs started glitching due to clock drift in
> > about an hour in my Pioneer DJ DDJ-SR2.
> >
> > Once again I'd like to thank Takashi Iwai. He's the true author of the
> bulk
> > of this code, I just adapted it and coerced it into working.
> >
> > Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
>
> Thank you Geraldo and Takashi for working on this patch. I'm currently
> in the process of testing with the DJM-750 but it currently does not
> work as expected. I'll debug futher and report back but would like to
> make you aware of this in the meantime. It may not be a a fundamental
> issue with the patch, but rather something incidental.
>
> Kind regards,
> Olivia
>
Takashi Iwai April 16, 2021, 4:11 p.m. UTC | #6
On Fri, 09 Apr 2021 13:07:45 +0200,
Olivia Mackintosh wrote:
> 
> On Mon, Apr 05, 2021 at 10:49:20AM -0300, Geraldo wrote:
> > Dear Linux users of Pioneer gear, please disregard v1 of this patch and
> > test this instead if at all possible.
> > 
> > My initial assessment that we needed to let the capture EP be opened twice
> > was clearly proven wrong by further testing. This is good because if we
> > really needed that it would require a lot of reengineering inside ALSA.
> > 
> > One thing that still boggles my mind though is why we need a special
> > Pioneer case inside snd_usb_parse_implicit_fb_quirk that returns 1 like a
> > capture quirk was found.
> > 
> > This is a highly experimental patch on top of 5.12-rc6 that's supposed to
> > engage implicit feedback sync on the playback for Pioneer devices. Without
> > implicit feedback sync the inputs started glitching due to clock drift in
> > about an hour in my Pioneer DJ DDJ-SR2.
> > 
> > Once again I'd like to thank Takashi Iwai. He's the true author of the bulk
> > of this code, I just adapted it and coerced it into working.
> > 
> > Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
> 
> Thank you Geraldo and Takashi for working on this patch. I'm currently
> in the process of testing with the DJM-750 but it currently does not
> work as expected. I'll debug futher and report back but would like to
> make you aware of this in the meantime. It may not be a a fundamental
> issue with the patch, but rather something incidental.

Which kernel version have you tested?  There have been quite a few
development about USB-audio recently, so something might be missing or
conflicting?  Let's see.

FWIW, below is a proper patch that is applied on top of for-next
branch of sound.git tree (destined for 5.13 kernel merge).


Takashi

-- 8< --
From: Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] ALSA: usb-audio: Re-apply implicit feedback mode to Pioneer
 devices

Pioneer devices are supposed to be working with the implicit feedback
mode, but so far the attempt to applying this caused issues, hence we
explicitly skipped the implicit feedback mode for them.  Recently,
Geraldo discovered that the device actually works if you skip the
generic matching of the sync EPs for the capture stream.  That is, we
should apply the implicit feedback setup for the playback like other
similar devices, while we need to return 1 from
audioformat_capture_quirk() so that no further matching will be done.

This patch implement the application of the implicit feedback to
Pioneer devices.  The former skip_pioneer_sync_ep() was dropped, and
instead we provide is_pioneer_implicit_fb() to check the Pioneer
devices that need the implicit feedback.  In the
audioformat_implicit_fb_quirk(), simply apply the implicit fb for
playback if matching, and in audioformat_capture_quirk()(), it returns
1 if matching, as mentioned in the above.

Reported-by: Geraldo <geraldogabriel@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/usb/implicit.c | 42 ++++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/sound/usb/implicit.c b/sound/usb/implicit.c
index 4bd9c105a529..427ed0ff3b7b 100644
--- a/sound/usb/implicit.c
+++ b/sound/usb/implicit.c
@@ -171,18 +171,27 @@ static int add_roland_implicit_fb(struct snd_usb_audio *chip,
 				       ifnum, alts);
 }
 
-/* Playback and capture EPs on Pioneer devices share the same iface/altset,
- * but they don't seem working with the implicit fb mode well, hence we
- * just return as if the sync were already set up.
+/* Playback and capture EPs on Pioneer devices share the same iface/altset
+ * for the implicit feedback operation
  */
-static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
-				struct audioformat *fmt,
-				struct usb_host_interface *alts)
+static bool is_pioneer_implicit_fb(struct snd_usb_audio *chip,
+				   struct usb_host_interface *alts)
+
 {
 	struct usb_endpoint_descriptor *epd;
 
+	if (USB_ID_VENDOR(chip->usb_id) != 0x2b73 &&
+	    USB_ID_VENDOR(chip->usb_id) != 0x08e4)
+		return false;
+	if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
+		return false;
 	if (alts->desc.bNumEndpoints != 2)
-		return 0;
+		return false;
+
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_out(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return false;
 
 	epd = get_endpoint(alts, 1);
 	if (!usb_endpoint_is_isoc_in(epd) ||
@@ -191,8 +200,9 @@ static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
 	     USB_ENDPOINT_USAGE_DATA &&
 	     (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
 	     USB_ENDPOINT_USAGE_IMPLICIT_FB))
-		return 0;
-	return 1; /* don't handle with the implicit fb, just skip sync EP */
+		return false;
+
+	return true;
 }
 
 static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
@@ -308,13 +318,11 @@ static int audioformat_implicit_fb_quirk(struct snd_usb_audio *chip,
 	}
 
 	/* Pioneer devices with vendor spec class */
-	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
-	    alts->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
-	    (USB_ID_VENDOR(chip->usb_id) == 0x2b73 || /* Pioneer */
-	     USB_ID_VENDOR(chip->usb_id) == 0x08e4    /* Pioneer */)) {
-		if (skip_pioneer_sync_ep(chip, fmt, alts))
-			return 1;
-	}
+	if (is_pioneer_implicit_fb(chip, alts))
+		return add_implicit_fb_sync_ep(chip, fmt,
+					       get_endpoint(alts, 1)->bEndpointAddress,
+					       1, alts->desc.bInterfaceNumber,
+					       alts);
 
 	/* Try the generic implicit fb if available */
 	if (chip->generic_implicit_fb)
@@ -335,6 +343,8 @@ static int audioformat_capture_quirk(struct snd_usb_audio *chip,
 	if (p && (p->type == IMPLICIT_FB_FIXED || p->type == IMPLICIT_FB_BOTH))
 		return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
 					       p->iface, NULL);
+	if (is_pioneer_implicit_fb(chip, alts))
+		return 1; /* skip */
 	return 0;
 }
Olivia Mackintosh April 17, 2021, 10:26 p.m. UTC | #7
> Which kernel version have you tested?  There have been quite a few
> development about USB-audio recently, so something might be missing or
> conflicting?  Let's see.

I have just tested d86f43b17ed4cd751f73d890ea63f818ffa5ef3d with and
without the patch:

  - Without the patch, everything works fine.
  - With the patch, speaker-test times out. I'll try to collect some more
    infomation from dyndb and try to have a look to see what the problem
    is.

There's no obvious mistakes in the patch as far as I can tell.

Olivia
Geraldo Nascimento April 18, 2021, 12:48 a.m. UTC | #8
Sorry to hear that, Olivia.

I have to ask, though, is capture working for your device? If not, then it
might be related.

Em Sáb, 17 de abr de 2021 19:28, Olivia Mackintosh <livvy@base.nu> escreveu:

> > Which kernel version have you tested?  There have been quite a few
> > development about USB-audio recently, so something might be missing or
> > conflicting?  Let's see.
>
> I have just tested d86f43b17ed4cd751f73d890ea63f818ffa5ef3d with and
> without the patch:
>
>   - Without the patch, everything works fine.
>   - With the patch, speaker-test times out. I'll try to collect some more
>     infomation from dyndb and try to have a look to see what the problem
>     is.
>
> There's no obvious mistakes in the patch as far as I can tell.
>
> Olivia
>
Takashi Iwai April 18, 2021, 7:43 a.m. UTC | #9
On Sun, 18 Apr 2021 00:24:21 +0200,
Olivia Mackintosh wrote:
> 
> > Which kernel version have you tested?  There have been quite a few
> > development about USB-audio recently, so something might be missing or
> > conflicting?  Let's see.
> 
> I have just tested d86f43b17ed4cd751f73d890ea63f818ffa5ef3d with and
> without the patch:
> 
>   - Without the patch, everything works fine.
>   - With the patch, speaker-test times out. I'll try to collect some more
>     infomation from dyndb and try to have a look to see what the problem
>     is.
> 
> There's no obvious mistakes in the patch as far as I can tell.

Thanks for testing.  A possible difference of speaker-test from others
is that speaker-test tends to set up with the larger period and buffer
sizes.  I guess the same problem could be seen when you run aplay with
the same parameters shown in /proc/asound/card*/pcm0p/sub0/hw_params,
too.

As a blind shot: might the stall be avoided by passing the recently
introduced chip->playback_first flag?  The revised patch is below.


Takashi

---
--- a/sound/usb/implicit.c
+++ b/sound/usb/implicit.c
@@ -230,18 +230,27 @@ static int add_roland_implicit_fb(struct snd_usb_audio *chip,
 				       ifnum, alts);
 }
 
-/* Playback and capture EPs on Pioneer devices share the same iface/altset,
- * but they don't seem working with the implicit fb mode well, hence we
- * just return as if the sync were already set up.
+/* Playback and capture EPs on Pioneer devices share the same iface/altset
+ * for the implicit feedback operation
  */
-static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
-				struct audioformat *fmt,
-				struct usb_host_interface *alts)
+static bool is_pioneer_implicit_fb(struct snd_usb_audio *chip,
+				   struct usb_host_interface *alts)
+
 {
 	struct usb_endpoint_descriptor *epd;
 
+	if (USB_ID_VENDOR(chip->usb_id) != 0x2b73 &&
+	    USB_ID_VENDOR(chip->usb_id) != 0x08e4)
+		return false;
+	if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
+		return false;
 	if (alts->desc.bNumEndpoints != 2)
-		return 0;
+		return false;
+
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_out(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return false;
 
 	epd = get_endpoint(alts, 1);
 	if (!usb_endpoint_is_isoc_in(epd) ||
@@ -250,8 +259,9 @@ static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
 	     USB_ENDPOINT_USAGE_DATA &&
 	     (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
 	     USB_ENDPOINT_USAGE_IMPLICIT_FB))
-		return 0;
-	return 1; /* don't handle with the implicit fb, just skip sync EP */
+		return false;
+
+	return true;
 }
 
 static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
@@ -367,12 +377,12 @@ static int audioformat_implicit_fb_quirk(struct snd_usb_audio *chip,
 	}
 
 	/* Pioneer devices with vendor spec class */
-	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
-	    alts->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
-	    (USB_ID_VENDOR(chip->usb_id) == 0x2b73 || /* Pioneer */
-	     USB_ID_VENDOR(chip->usb_id) == 0x08e4    /* Pioneer */)) {
-		if (skip_pioneer_sync_ep(chip, fmt, alts))
-			return 1;
+	if (is_pioneer_implicit_fb(chip, alts)) {
+		chip->playback_first = 1;
+		return add_implicit_fb_sync_ep(chip, fmt,
+					       get_endpoint(alts, 1)->bEndpointAddress,
+					       1, alts->desc.bInterfaceNumber,
+					       alts);
 	}
 
 	/* Try the generic implicit fb if available */
@@ -394,6 +404,8 @@ static int audioformat_capture_quirk(struct snd_usb_audio *chip,
 	if (p && (p->type == IMPLICIT_FB_FIXED || p->type == IMPLICIT_FB_BOTH))
 		return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
 					       p->iface, NULL);
+	if (is_pioneer_implicit_fb(chip, alts))
+		return 1; /* skip */
 	return 0;
 }
Olivia Mackintosh April 18, 2021, 12:43 p.m. UTC | #10
> As a blind shot: might the stall be avoided by passing the recently
> introduced chip->playback_first flag?  The revised patch is below.

This appears to fix the issue, thank you! I am curious as to why this is
not required for Geraldo's DDJ-SR2.

My initial thought was that certain devices that restrict capture unless
regular SysEx/Control URBs are sent may mean that Playback first support
is required (e.g. 750, 850, 450). Please correct me if this intuition is
incorrect.

Olivia
Geraldo Nascimento April 18, 2021, 2:16 p.m. UTC | #11
Em Dom, 18 de abr de 2021 09:45, Olivia Mackintosh <livvy@base.nu> escreveu:

> > As a blind shot: might the stall be avoided by passing the recently
> > introduced chip->playback_first flag?  The revised patch is below.
>
> This appears to fix the issue, thank you! I am curious as to why this is
> not required for Geraldo's DDJ-SR2.
>

Heh, sometimes I think Takashi Iwai is psychic ;-)

Just kidding, he's "just" very talented and very experienced. Anyway, the
DDJ-SR2 is originally a Serato controller. It still requires two MIDI SysEx
messages to unmute the RCA inputs - engaging "Serato Mode" in
marketing-speak.

My point is that Pioneer may be a little more compliant / a little less
deviant from the UAC2 standard when designing gear for use with third-party
software.


> My initial thought was that certain devices that restrict capture unless
> regular SysEx/Control URBs are sent may mean that Playback first support
> is required (e.g. 750, 850, 450). Please correct me if this intuition is
> incorrect.


> Olivia
>
Takashi Iwai April 19, 2021, 7:15 a.m. UTC | #12
On Sun, 18 Apr 2021 16:16:56 +0200,
Geraldo Nascimento wrote:
> 
> Em Dom, 18 de abr de 2021 09:45, Olivia Mackintosh <livvy@base.nu> escreveu:
> 
>     > As a blind shot: might the stall be avoided by passing the recently
>     > introduced chip->playback_first flag?  The revised patch is below.
>    
>     This appears to fix the issue, thank you! I am curious as to why this is
>     not required for Geraldo's DDJ-SR2.
> 
> Heh, sometimes I think Takashi Iwai is psychic ;-)

Heh, it was our luck that we've worked on the similar problem very
recently.

> Just kidding, he's "just" very talented and very experienced. Anyway, the
> DDJ-SR2 is originally a Serato controller. It still requires two MIDI SysEx
> messages to unmute the RCA inputs - engaging "Serato Mode" in marketing-speak.
> 
> My point is that Pioneer may be a little more compliant / a little less
> deviant from the UAC2 standard when designing gear for use with third-party
> software.

I think many devices require the implicit feedback seem following this
pattern: for such devices, the full-duplex streams are mandatory,
i.e. both streams have to be started always.  And the implicit
feedback is triggered at the later point for a proper sync.

>     My initial thought was that certain devices that restrict capture unless
>     regular SysEx/Control URBs are sent may mean that Playback first support
>     is required (e.g. 750, 850, 450). Please correct me if this intuition is
>     incorrect.

As mentioned previously, it might be the difference of the PCM
parameters to be deployed.  I guess Geraldo didn't test speaker-test
program but maybe only the standard sound backends like JACK, etc.

In anyway, I'm going to format and submit the proper patch for
merging.


thanks,

Takashi
diff mbox series

Patch

--- implicit.c.git      2021-04-04 20:51:57.226754632 -0300
+++ implicit.c  2021-04-05 10:02:41.059816581 -0300
@@ -177,30 +177,31 @@  static int add_roland_implicit_fb(struct
                                       ifnum, alts);
 }

-/* Playback and capture EPs on Pioneer devices share the same iface/altset,
- * but they don't seem working with the implicit fb mode well, hence we
- * just return as if the sync were already set up.
+/* Pioneer devices: playback and capture streams sharing the same
iface/altset
  */
-static int skip_pioneer_sync_ep(struct snd_usb_audio *chip,
-                               struct audioformat *fmt,
-                               struct usb_host_interface *alts)
-{
-       struct usb_endpoint_descriptor *epd;
-
-       if (alts->desc.bNumEndpoints != 2)
-               return 0;
-
-       epd = get_endpoint(alts, 1);
-       if (!usb_endpoint_is_isoc_in(epd) ||
-           (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) !=
USB_ENDPOINT_SYNC_ASYNC ||
-           ((epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
-            USB_ENDPOINT_USAGE_DATA &&
-            (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
-            USB_ENDPOINT_USAGE_IMPLICIT_FB))
-               return 0;
-       return 1; /* don't handle with the implicit fb, just skip sync EP */
+static int add_pioneer_implicit_fb(struct snd_usb_audio *chip,
+                                  struct audioformat *fmt,
+                                  struct usb_host_interface *alts)
+{
+       struct usb_endpoint_descriptor *epd;
+
+       if (alts->desc.bNumEndpoints != 2)
+               return 0;
+
+       epd = get_endpoint(alts, 1);
+
+       if (!usb_endpoint_is_isoc_in(epd) ||
+           (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) !=
USB_ENDPOINT_SYNC_ASYNC ||
+           ((epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
+            USB_ENDPOINT_USAGE_DATA &&
+            (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
+            USB_ENDPOINT_USAGE_IMPLICIT_FB))
+               return 0;
+       return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 1,
+                                      alts->desc.bInterfaceNumber, alts);
 }

+