diff mbox series

[v2] Bluetooth: btusb: check conditions before enabling USB ALT 3 for WBS

Message ID b86543908684cc6cd9afaf4de10fac7af1a49665.camel@iki.fi (mailing list archive)
State Superseded
Headers show
Series [v2] Bluetooth: btusb: check conditions before enabling USB ALT 3 for WBS | expand

Commit Message

Pauli Virtanen July 23, 2021, 10:07 a.m. UTC
Some USB BT adapters don't satisfy the MTU requirement mentioned in
commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
and have ALT 3 setting that produces no/garbled audio. Some adapters
with larger MTU were also reported to have problems with ALT 3.

Add a flag and check it and MTU before selecting ALT 3, falling back to
ALT 1. Enable the flag for Realtek, restoring the previous behavior for
non-Realtek devices.

Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1
works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3
works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling
ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad
audio) Intel 8087:0a2b.

Signed-off-by: Pauli Virtanen <pav@iki.fi>
Fixes: e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
---

Changes in v2:
- Explain magic number 72 in a comment; didn't add the table for them,
  because it's not used elsewhere and we need just one number from it.
- Add flag for ALT3 support, restoring the behavior
  for non-Realtek devices the same as before e848dbd364ac, due to
  the problems reported on an Intel adapter. Don't have the device
  myself.

 drivers/bluetooth/btusb.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

Comments

Marcel Holtmann July 23, 2021, 12:19 p.m. UTC | #1
Hi Pauli,

> Some USB BT adapters don't satisfy the MTU requirement mentioned in
> commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
> and have ALT 3 setting that produces no/garbled audio. Some adapters
> with larger MTU were also reported to have problems with ALT 3.
> 
> Add a flag and check it and MTU before selecting ALT 3, falling back to
> ALT 1. Enable the flag for Realtek, restoring the previous behavior for
> non-Realtek devices.
> 
> Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1
> works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3
> works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling
> ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad
> audio) Intel 8087:0a2b.
> 
> Signed-off-by: Pauli Virtanen <pav@iki.fi>
> Fixes: e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")

before I will apply this, I need Tested-by or Ack-by people that confirm that this fixes their issues now.

> ---
> 
> Changes in v2:
> - Explain magic number 72 in a comment; didn't add the table for them,
>  because it's not used elsewhere and we need just one number from it.
> - Add flag for ALT3 support, restoring the behavior
>  for non-Realtek devices the same as before e848dbd364ac, due to
>  the problems reported on an Intel adapter. Don't have the device
>  myself.
> 
> drivers/bluetooth/btusb.c | 22 ++++++++++++++--------
> 1 file changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 6d23308119d1..5cec719f6cba 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -516,6 +516,7 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
> #define BTUSB_HW_RESET_ACTIVE	12
> #define BTUSB_TX_WAIT_VND_EVT	13
> #define BTUSB_WAKEUP_DISABLE	14
> +#define BTUSB_ALT3_OK_FOR_WBS	15

Rename this to BTUSB_USE_ALT3_FOR_WBS.

> 
> struct btusb_data {
> 	struct hci_dev       *hdev;
> @@ -1748,16 +1749,20 @@ static void btusb_work(struct work_struct *work)
> 			/* Bluetooth USB spec recommends alt 6 (63 bytes), but
> 			 * many adapters do not support it.  Alt 1 appears to
> 			 * work for all adapters that do not have alt 6, and
> -			 * which work with WBS at all.
> +			 * which work with WBS at all.  Some devices prefer
> +			 * alt 3 (HCI payload >= 60 Bytes let air packet
> +			 * data satisfy 60 bytes), requiring
> +			 * MTU >= 3 (packets) * 25 (size) - 3 (headers) = 72
> +			 * see also Core spec 5, vol 4, B 2.1.1 & Table 2.1.
> 			 */
> -			new_alts = btusb_find_altsetting(data, 6) ? 6 : 1;
> -			/* Because mSBC frames do not need to be aligned to the
> -			 * SCO packet boundary. If support the Alt 3, use the
> -			 * Alt 3 for HCI payload >= 60 Bytes let air packet
> -			 * data satisfy 60 bytes.
> -			 */
> -			if (new_alts == 1 && btusb_find_altsetting(data, 3))
> +			if (btusb_find_altsetting(data, 6))
> +				new_alts = 6;
> +			else if (test_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags) &&
> +				 hdev->sco_mtu >= 72 &&
> +				 btusb_find_altsetting(data, 3))

This is whitespace damaged.

> 				new_alts = 3;
> +			else
> +				new_alts = 1;
> 		}
> 
> 		if (btusb_switch_alt_setting(hdev, new_alts) < 0)
> @@ -4733,6 +4738,7 @@ static int btusb_probe(struct usb_interface *intf,
> 		 * (DEVICE_REMOTE_WAKEUP)
> 		 */
> 		set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
> +		set_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags);
> 	}

Regards

Marcel
Michał Kępień July 25, 2021, 5:47 a.m. UTC | #2
> > Some USB BT adapters don't satisfy the MTU requirement mentioned in
> > commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
> > and have ALT 3 setting that produces no/garbled audio. Some adapters
> > with larger MTU were also reported to have problems with ALT 3.
> > 
> > Add a flag and check it and MTU before selecting ALT 3, falling back to
> > ALT 1. Enable the flag for Realtek, restoring the previous behavior for
> > non-Realtek devices.
> > 
> > Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1
> > works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3
> > works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling
> > ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad
> > audio) Intel 8087:0a2b.
> > 
> > Signed-off-by: Pauli Virtanen <pav@iki.fi>
> > Fixes: e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
> 
> before I will apply this, I need Tested-by or Ack-by people that confirm that this fixes their issues now.

For 8087:0a2b (with broken mSBC audio since e848dbd364ac):

Tested-by: Michał Kępień <kernel@kempniu.pl>

It would be nice to get this into the stable tree as e848dbd364ac got
there in v5.13.3 (as 15407b14e27b) and v5.10.51 (as 05298f1733c6).

Thanks!
Pasi Kärkkäinen Aug. 10, 2021, 4:48 p.m. UTC | #3
Hello Marcel,

On Fri, Jul 23, 2021 at 02:19:09PM +0200, Marcel Holtmann wrote:
> Hi Pauli,
> 
> > Some USB BT adapters don't satisfy the MTU requirement mentioned in
> > commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
> > and have ALT 3 setting that produces no/garbled audio. Some adapters
> > with larger MTU were also reported to have problems with ALT 3.
> > 
> > Add a flag and check it and MTU before selecting ALT 3, falling back to
> > ALT 1. Enable the flag for Realtek, restoring the previous behavior for
> > non-Realtek devices.
> > 
> > Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1
> > works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3
> > works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling
> > ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad
> > audio) Intel 8087:0a2b.
> > 
> > Signed-off-by: Pauli Virtanen <pav@iki.fi>
> > Fixes: e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
> 
> before I will apply this, I need Tested-by or Ack-by people that confirm that this fixes their issues now.
>

Is v3 ok/enough? It has one Tested-by.
It would probably be good to send v4 anyway with CC stable@kernel.org ..


Thanks,

-- Pasi

> 
> > ---
> > 
> > Changes in v2:
> > - Explain magic number 72 in a comment; didn't add the table for them,
> >  because it's not used elsewhere and we need just one number from it.
> > - Add flag for ALT3 support, restoring the behavior
> >  for non-Realtek devices the same as before e848dbd364ac, due to
> >  the problems reported on an Intel adapter. Don't have the device
> >  myself.
> > 
> > drivers/bluetooth/btusb.c | 22 ++++++++++++++--------
> > 1 file changed, 14 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> > index 6d23308119d1..5cec719f6cba 100644
> > --- a/drivers/bluetooth/btusb.c
> > +++ b/drivers/bluetooth/btusb.c
> > @@ -516,6 +516,7 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
> > #define BTUSB_HW_RESET_ACTIVE	12
> > #define BTUSB_TX_WAIT_VND_EVT	13
> > #define BTUSB_WAKEUP_DISABLE	14
> > +#define BTUSB_ALT3_OK_FOR_WBS	15
> 
> Rename this to BTUSB_USE_ALT3_FOR_WBS.
> 
> > 
> > struct btusb_data {
> > 	struct hci_dev       *hdev;
> > @@ -1748,16 +1749,20 @@ static void btusb_work(struct work_struct *work)
> > 			/* Bluetooth USB spec recommends alt 6 (63 bytes), but
> > 			 * many adapters do not support it.  Alt 1 appears to
> > 			 * work for all adapters that do not have alt 6, and
> > -			 * which work with WBS at all.
> > +			 * which work with WBS at all.  Some devices prefer
> > +			 * alt 3 (HCI payload >= 60 Bytes let air packet
> > +			 * data satisfy 60 bytes), requiring
> > +			 * MTU >= 3 (packets) * 25 (size) - 3 (headers) = 72
> > +			 * see also Core spec 5, vol 4, B 2.1.1 & Table 2.1.
> > 			 */
> > -			new_alts = btusb_find_altsetting(data, 6) ? 6 : 1;
> > -			/* Because mSBC frames do not need to be aligned to the
> > -			 * SCO packet boundary. If support the Alt 3, use the
> > -			 * Alt 3 for HCI payload >= 60 Bytes let air packet
> > -			 * data satisfy 60 bytes.
> > -			 */
> > -			if (new_alts == 1 && btusb_find_altsetting(data, 3))
> > +			if (btusb_find_altsetting(data, 6))
> > +				new_alts = 6;
> > +			else if (test_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags) &&
> > +				 hdev->sco_mtu >= 72 &&
> > +				 btusb_find_altsetting(data, 3))
> 
> This is whitespace damaged.
> 
> > 				new_alts = 3;
> > +			else
> > +				new_alts = 1;
> > 		}
> > 
> > 		if (btusb_switch_alt_setting(hdev, new_alts) < 0)
> > @@ -4733,6 +4738,7 @@ static int btusb_probe(struct usb_interface *intf,
> > 		 * (DEVICE_REMOTE_WAKEUP)
> > 		 */
> > 		set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
> > +		set_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags);
> > 	}
> 
> Regards
> 
> Marcel
>
Luiz Augusto von Dentz Aug. 10, 2021, 6:37 p.m. UTC | #4
Hi Pasi, Pauli,

On Tue, Aug 10, 2021 at 9:50 AM Pasi Kärkkäinen <pasik@iki.fi> wrote:
>
> Hello Marcel,
>
> On Fri, Jul 23, 2021 at 02:19:09PM +0200, Marcel Holtmann wrote:
> > Hi Pauli,
> >
> > > Some USB BT adapters don't satisfy the MTU requirement mentioned in
> > > commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
> > > and have ALT 3 setting that produces no/garbled audio. Some adapters
> > > with larger MTU were also reported to have problems with ALT 3.
> > >
> > > Add a flag and check it and MTU before selecting ALT 3, falling back to
> > > ALT 1. Enable the flag for Realtek, restoring the previous behavior for
> > > non-Realtek devices.
> > >
> > > Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1
> > > works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3
> > > works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling
> > > ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad
> > > audio) Intel 8087:0a2b.
> > >
> > > Signed-off-by: Pauli Virtanen <pav@iki.fi>
> > > Fixes: e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS")
> >
> > before I will apply this, I need Tested-by or Ack-by people that confirm that this fixes their issues now.
> >
>
> Is v3 ok/enough? It has one Tested-by.
> It would probably be good to send v4 anyway with CC stable@kernel.org ..
>
>
> Thanks,
>
> -- Pasi
>
> >
> > > ---
> > >
> > > Changes in v2:
> > > - Explain magic number 72 in a comment; didn't add the table for them,
> > >  because it's not used elsewhere and we need just one number from it.
> > > - Add flag for ALT3 support, restoring the behavior
> > >  for non-Realtek devices the same as before e848dbd364ac, due to
> > >  the problems reported on an Intel adapter. Don't have the device
> > >  myself.
> > >
> > > drivers/bluetooth/btusb.c | 22 ++++++++++++++--------
> > > 1 file changed, 14 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> > > index 6d23308119d1..5cec719f6cba 100644
> > > --- a/drivers/bluetooth/btusb.c
> > > +++ b/drivers/bluetooth/btusb.c
> > > @@ -516,6 +516,7 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
> > > #define BTUSB_HW_RESET_ACTIVE       12
> > > #define BTUSB_TX_WAIT_VND_EVT       13
> > > #define BTUSB_WAKEUP_DISABLE        14
> > > +#define BTUSB_ALT3_OK_FOR_WBS      15
> >
> > Rename this to BTUSB_USE_ALT3_FOR_WBS.
> >
> > >
> > > struct btusb_data {
> > >     struct hci_dev       *hdev;
> > > @@ -1748,16 +1749,20 @@ static void btusb_work(struct work_struct *work)
> > >                     /* Bluetooth USB spec recommends alt 6 (63 bytes), but
> > >                      * many adapters do not support it.  Alt 1 appears to
> > >                      * work for all adapters that do not have alt 6, and
> > > -                    * which work with WBS at all.
> > > +                    * which work with WBS at all.  Some devices prefer
> > > +                    * alt 3 (HCI payload >= 60 Bytes let air packet
> > > +                    * data satisfy 60 bytes), requiring
> > > +                    * MTU >= 3 (packets) * 25 (size) - 3 (headers) = 72
> > > +                    * see also Core spec 5, vol 4, B 2.1.1 & Table 2.1.
> > >                      */
> > > -                   new_alts = btusb_find_altsetting(data, 6) ? 6 : 1;
> > > -                   /* Because mSBC frames do not need to be aligned to the
> > > -                    * SCO packet boundary. If support the Alt 3, use the
> > > -                    * Alt 3 for HCI payload >= 60 Bytes let air packet
> > > -                    * data satisfy 60 bytes.
> > > -                    */
> > > -                   if (new_alts == 1 && btusb_find_altsetting(data, 3))
> > > +                   if (btusb_find_altsetting(data, 6))
> > > +                           new_alts = 6;
> > > +                   else if (test_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags) &&
> > > +                            hdev->sco_mtu >= 72 &&
> > > +                            btusb_find_altsetting(data, 3))
> >
> > This is whitespace damaged.

Ive fixed this and made it fit in 80 columns by reordering the checks.

> >
> > >                             new_alts = 3;
> > > +                   else
> > > +                           new_alts = 1;
> > >             }
> > >
> > >             if (btusb_switch_alt_setting(hdev, new_alts) < 0)
> > > @@ -4733,6 +4738,7 @@ static int btusb_probe(struct usb_interface *intf,
> > >              * (DEVICE_REMOTE_WAKEUP)
> > >              */
> > >             set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
> > > +           set_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags);
> > >     }
> >
> > Regards
> >
> > Marcel

Applied, thanks.
diff mbox series

Patch

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 6d23308119d1..5cec719f6cba 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -516,6 +516,7 @@  static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
 #define BTUSB_HW_RESET_ACTIVE	12
 #define BTUSB_TX_WAIT_VND_EVT	13
 #define BTUSB_WAKEUP_DISABLE	14
+#define BTUSB_ALT3_OK_FOR_WBS	15
 
 struct btusb_data {
 	struct hci_dev       *hdev;
@@ -1748,16 +1749,20 @@  static void btusb_work(struct work_struct *work)
 			/* Bluetooth USB spec recommends alt 6 (63 bytes), but
 			 * many adapters do not support it.  Alt 1 appears to
 			 * work for all adapters that do not have alt 6, and
-			 * which work with WBS at all.
+			 * which work with WBS at all.  Some devices prefer
+			 * alt 3 (HCI payload >= 60 Bytes let air packet
+			 * data satisfy 60 bytes), requiring
+			 * MTU >= 3 (packets) * 25 (size) - 3 (headers) = 72
+			 * see also Core spec 5, vol 4, B 2.1.1 & Table 2.1.
 			 */
-			new_alts = btusb_find_altsetting(data, 6) ? 6 : 1;
-			/* Because mSBC frames do not need to be aligned to the
-			 * SCO packet boundary. If support the Alt 3, use the
-			 * Alt 3 for HCI payload >= 60 Bytes let air packet
-			 * data satisfy 60 bytes.
-			 */
-			if (new_alts == 1 && btusb_find_altsetting(data, 3))
+			if (btusb_find_altsetting(data, 6))
+				new_alts = 6;
+			else if (test_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags) &&
+				 hdev->sco_mtu >= 72 &&
+				 btusb_find_altsetting(data, 3))
 				new_alts = 3;
+			else
+				new_alts = 1;
 		}
 
 		if (btusb_switch_alt_setting(hdev, new_alts) < 0)
@@ -4733,6 +4738,7 @@  static int btusb_probe(struct usb_interface *intf,
 		 * (DEVICE_REMOTE_WAKEUP)
 		 */
 		set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
+		set_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags);
 	}
 
 	if (!reset)