| Message ID | 20220803090218.1313187-1-kkamagui@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | net: usb: cdc_mbim: adding Microsoft mobile broadband modem | expand |
Hello Seunghun, Il giorno mer 3 ago 2022 alle ore 11:10 Seunghun Han <kkamagui@gmail.com> ha scritto: > > Microsoft branded mobile broadband modems typically used in the Surface series > don't work with the Linux kernel. When I query firmware information to the > modem using the mbimcli tool, it always returns the Failure (0x02) value like > below. > > === Start of the firmware id query === > $> mbimcli -d /dev/cdc-wdm4 --ms-query-firmware-id -v > [26 Jul 2022, 05:24:07] [Debug] opening device... > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Queried max control message size: 4096 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Sent message... > <<<<<< RAW: > <<<<<< length = 16 > <<<<<< data = 01:00:00:00:10:00:00:00:01:00:00:00:00:10:00:00 > > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Sent message (translated)... > <<<<<< Header: > <<<<<< length = 16 > <<<<<< type = open (0x00000001) > <<<<<< transaction = 1 > <<<<<< Contents: > <<<<<< max control transfer = 4096 > > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Received message... > >>>>>> RAW: > >>>>>> length = 16 > >>>>>> data = 01:00:00:80:10:00:00:00:01:00:00:00:02:00:00:00 > > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Received message...Message Type 80000001 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 864 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 897 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 923 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 930 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 935 > [26 Jul 2022, 05:24:07] [Debug] getting open done result failed: closed > error: couldn't open the MbimDevice: Failure > === End of the firmware id query === > > After kernel debugging, I found that the modem reported that the dwNtbInMaxSize > value of ncm_parm was 16384 during the initialization sequence. > So the cdc_ncm_update_rxtx_max() in cdc_ncm_bind_common() didn't send > USB_CDC_SET_NTB_INPUT_SIZE command because the default input size was the same, > 16384. > > It's good and proper behavior. However, Microsoft branded MBMs (including the > latest one in Surface Go 3) fail until the kernel explicitly sets the input > size. > > This patch adds a new table and code changes that explicitly send > the USB_CDC_SET_NTB_INPUT_SIZE command to support Microsoft branded MBMs. > Just for reference, are you allowed to disclose which chipsets these modems are based on? Thanks, Daniele > Signed-off-by: Seunghun Han <kkamagui@gmail.com> > --- > drivers/net/usb/cdc_mbim.c | 24 ++++++++++++++++++++++++ > drivers/net/usb/cdc_ncm.c | 2 +- > include/linux/usb/cdc_ncm.h | 1 + > 3 files changed, 26 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c > index c89639381eca..c0c23cfc02a7 100644 > --- a/drivers/net/usb/cdc_mbim.c > +++ b/drivers/net/usb/cdc_mbim.c > @@ -618,6 +618,22 @@ static const struct driver_info cdc_mbim_info_avoid_altsetting_toggle = { > .data = CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE, > }; > > +/* Microsoft branded modems do not work properly without setting the input size > + * explicitly in cdc_ncm_bind_common. > + * CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY flag is used to set the input size > + * during initialization. > + */ > +static const struct driver_info cdc_mbim_info_set_input_size_explicitly = { > + .description = "CDC MBIM", > + .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP, > + .bind = cdc_mbim_bind, > + .unbind = cdc_mbim_unbind, > + .manage_power = cdc_mbim_manage_power, > + .rx_fixup = cdc_mbim_rx_fixup, > + .tx_fixup = cdc_mbim_tx_fixup, > + .data = CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY, > +}; > + > static const struct usb_device_id mbim_devs[] = { > /* This duplicate NCM entry is intentional. MBIM devices can > * be disguised as NCM by default, and this is necessary to > @@ -665,6 +681,14 @@ static const struct usb_device_id mbim_devs[] = { > .driver_info = (unsigned long)&cdc_mbim_info_avoid_altsetting_toggle, > }, > > + /* Some Microsoft branded mobile broadband modems used in the Surface > + * seires are known to fail unless the input size is set explicitly. > + * Applying it to all Microsoft branded MBMs. > + */ > + { USB_VENDOR_AND_INTERFACE_INFO(0x045e, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE), > + .driver_info = (unsigned long)&cdc_mbim_info_set_input_size_explicitly, > + }, > + > /* default entry */ > { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE), > .driver_info = (unsigned long)&cdc_mbim_info_zlp, > diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c > index 8d5cbda33f66..915e29c987cb 100644 > --- a/drivers/net/usb/cdc_ncm.c > +++ b/drivers/net/usb/cdc_ncm.c > @@ -407,7 +407,7 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx) > val = cdc_ncm_check_rx_max(dev, new_rx); > > /* inform device about NTB input size changes */ > - if (val != ctx->rx_max) { > + if (val != ctx->rx_max || ctx->drvflags & CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY) { > __le32 dwNtbInMaxSize = cpu_to_le32(val); > > dev_info(&dev->intf->dev, "setting rx_max = %u\n", val); > diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h > index 2d207cb4837d..a24f84b31a54 100644 > --- a/include/linux/usb/cdc_ncm.h > +++ b/include/linux/usb/cdc_ncm.h > @@ -88,6 +88,7 @@ > #define CDC_NCM_FLAG_NDP_TO_END 0x02 /* NDP is placed at end of frame */ > #define CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE 0x04 /* Avoid altsetting toggle during init */ > #define CDC_NCM_FLAG_PREFER_NTB32 0x08 /* prefer NDP32 over NDP16 */ > +#define CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY 0x10 /* Set input size explicitly during init */ > > #define cdc_ncm_comm_intf_is_mbim(x) ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \ > (x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE) > -- > 2.30.2 >
Hello Daniele, On Wed, Aug 3, 2022 at 7:58 PM Daniele Palmas <dnlplm@gmail.com> wrote: > > Just for reference, are you allowed to disclose which chipsets these > modems are based on? > > Thanks, > Daniele I'm not sure which chipsets are used for them. In the Windows environment, the information that I could find was Microsoft Surface Mobile Broadband Modem. Some people guess they are based on Qualcomm Snapdragon X16 and successors, but I could find no evidence about them. If you know the way, would you tell me how I can find or confirm it? Best regards, Seunghun
Hello Seunghun, Il giorno mer 3 ago 2022 alle ore 14:56 Seunghun Han <kkamagui@gmail.com> ha scritto: > > Hello Daniele, > > On Wed, Aug 3, 2022 at 7:58 PM Daniele Palmas <dnlplm@gmail.com> wrote: > > > > Just for reference, are you allowed to disclose which chipsets these > > modems are based on? > > > > Thanks, > > Daniele > > I'm not sure which chipsets are used for them. In the Windows > environment, the information that I could find was Microsoft Surface > Mobile Broadband Modem. Some people guess they are based on Qualcomm > Snapdragon X16 and successors, but I could find no evidence about > them. > > If you know the way, would you tell me how I can find or confirm it? > Unfortunately I'm not aware of any specific place for that: I wrongly thought that you were involved in the development of the modem and you knew the chipset. However, sometimes the name of the chipset is left in the firmware revision: you can try looking if there's any hint in the output of the device caps request. If it's a Qualcomm modem it should probably also support QMI-over-MBIM service, so maybe you can also try a few DMS requests (--dms-get-software-version, --dms-get-revision...). Sometimes also the USB descriptors can be useful. Regards, Daniele > Best regards, > Seunghun
Hello Daniele, On Thu, Aug 4, 2022 at 4:07 PM Daniele Palmas <dnlplm@gmail.com> wrote: > > Unfortunately I'm not aware of any specific place for that: I wrongly > thought that you were involved in the development of the modem and you > knew the chipset. Thank you for thinking like that. However, I'm just a Linux lover and a Microsoft Surface user. > However, sometimes the name of the chipset is left in the firmware > revision: you can try looking if there's any hint in the output of the > device caps request. If it's a Qualcomm modem it should probably also > support QMI-over-MBIM service, so maybe you can also try a few DMS > requests (--dms-get-software-version, --dms-get-revision...). > > Sometimes also the USB descriptors can be useful. According to your guides, I did get some useful information from my Surface Go 3 modem. Finally, it was based on a Qualcomm chip, and other Microsoft mobile broadband modems should be based on the Qualcomm chip. The test results on my Surface Go 3 are below. ==== Start of test results ==== $> lsusb Bus 002 Device 004: ID 045e:09a5 Microsoft Corp. Surface $> lsbusb -t /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M |__ Port 1: Dev 5, If 0, Class=Hub, Driver=hub/4p, 5000M |__ Port 4: Dev 6, If 0, Class=Vendor Specific Class, Driver=r8152, 5000M |__ Port 3: Dev 4, If 0, Class=Communications, Driver=cdc_mbim, 5000M |__ Port 3: Dev 4, If 1, Class=CDC Data, Driver=cdc_mbim, 5000M |__ Port 3: Dev 4, If 2, Class=Vendor Specific Class, Driver=, 5000M $> qmicli --device=/dev/cdc-wdm3 --dms-get-manufacturer [/dev/cdc-wdm3] Device manufacturer retrieved: Manufacturer: 'QUALCOMM INCORPORATED' $> qmicli --device=/dev/cdc-wdm3 --dms-get-revision [/dev/cdc-wdm3] Device revision retrieved: Revision: '2140-e88e4b-c8-00004.36 1 [May 17 2021 01:00:00]' $> qmicli --device=/dev/cdc-wdm3 --dms-get-software-version [/dev/cdc-wdm3] Software version: 655_GEN_PACK-1.362573.1.400078.2 $> qmicli --device=/dev/cdc-wdm3 --dms-get-band-capabilities [/dev/cdc-wdm3] Device band capabilities retrieved: Bands: 'wcdma-2100, wcdma-pcs-1900, wcdma-850-us, wcdma-800, wcdma-900' LTE bands: '1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 19, 20, 25, 26, 28, 29, 30, 38, 39, 40, 41' LTE bands (extended): '1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 19, 20, 25, 26, 28, 29, 30, 38, 39, 40, 41, 66' $> qmicli --device=/dev/cdc-wdm3 --dms-get-capabilities [/dev/cdc-wdm3] Device capabilities retrieved: Max TX channel rate: '50000000' Max RX channel rate: '100000000' Data Service: 'non-simultaneous-cs-ps' SIM: 'supported' Networks: 'umts, lte' ==== End of test results ==== Thank you for your help. Best regards, Seunghun > Regards, > Daniele >
Does anyone have comments on my patch? If there are some points to improve, please let me know. I'm waiting for them. On Wed, Aug 3, 2022 at 6:02 PM Seunghun Han <kkamagui@gmail.com> wrote: > > Microsoft branded mobile broadband modems typically used in the Surface series > don't work with the Linux kernel. When I query firmware information to the > modem using the mbimcli tool, it always returns the Failure (0x02) value like > below. > > === Start of the firmware id query === > $> mbimcli -d /dev/cdc-wdm4 --ms-query-firmware-id -v > [26 Jul 2022, 05:24:07] [Debug] opening device... > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Queried max control message size: 4096 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Sent message... > <<<<<< RAW: > <<<<<< length = 16 > <<<<<< data = 01:00:00:00:10:00:00:00:01:00:00:00:00:10:00:00 > > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Sent message (translated)... > <<<<<< Header: > <<<<<< length = 16 > <<<<<< type = open (0x00000001) > <<<<<< transaction = 1 > <<<<<< Contents: > <<<<<< max control transfer = 4096 > > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Received message... > >>>>>> RAW: > >>>>>> length = 16 > >>>>>> data = 01:00:00:80:10:00:00:00:01:00:00:00:02:00:00:00 > > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Received message...Message Type 80000001 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 864 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 897 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 923 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 930 > [26 Jul 2022, 05:24:07] [Debug] [/dev/cdc-wdm4] Processing process_message 935 > [26 Jul 2022, 05:24:07] [Debug] getting open done result failed: closed > error: couldn't open the MbimDevice: Failure > === End of the firmware id query === > > After kernel debugging, I found that the modem reported that the dwNtbInMaxSize > value of ncm_parm was 16384 during the initialization sequence. > So the cdc_ncm_update_rxtx_max() in cdc_ncm_bind_common() didn't send > USB_CDC_SET_NTB_INPUT_SIZE command because the default input size was the same, > 16384. > > It's good and proper behavior. However, Microsoft branded MBMs (including the > latest one in Surface Go 3) fail until the kernel explicitly sets the input > size. > > This patch adds a new table and code changes that explicitly send > the USB_CDC_SET_NTB_INPUT_SIZE command to support Microsoft branded MBMs. > > Signed-off-by: Seunghun Han <kkamagui@gmail.com> > --- > drivers/net/usb/cdc_mbim.c | 24 ++++++++++++++++++++++++ > drivers/net/usb/cdc_ncm.c | 2 +- > include/linux/usb/cdc_ncm.h | 1 + > 3 files changed, 26 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c > index c89639381eca..c0c23cfc02a7 100644 > --- a/drivers/net/usb/cdc_mbim.c > +++ b/drivers/net/usb/cdc_mbim.c > @@ -618,6 +618,22 @@ static const struct driver_info cdc_mbim_info_avoid_altsetting_toggle = { > .data = CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE, > }; > > +/* Microsoft branded modems do not work properly without setting the input size > + * explicitly in cdc_ncm_bind_common. > + * CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY flag is used to set the input size > + * during initialization. > + */ > +static const struct driver_info cdc_mbim_info_set_input_size_explicitly = { > + .description = "CDC MBIM", > + .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP, > + .bind = cdc_mbim_bind, > + .unbind = cdc_mbim_unbind, > + .manage_power = cdc_mbim_manage_power, > + .rx_fixup = cdc_mbim_rx_fixup, > + .tx_fixup = cdc_mbim_tx_fixup, > + .data = CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY, > +}; > + > static const struct usb_device_id mbim_devs[] = { > /* This duplicate NCM entry is intentional. MBIM devices can > * be disguised as NCM by default, and this is necessary to > @@ -665,6 +681,14 @@ static const struct usb_device_id mbim_devs[] = { > .driver_info = (unsigned long)&cdc_mbim_info_avoid_altsetting_toggle, > }, > > + /* Some Microsoft branded mobile broadband modems used in the Surface > + * seires are known to fail unless the input size is set explicitly. > + * Applying it to all Microsoft branded MBMs. > + */ > + { USB_VENDOR_AND_INTERFACE_INFO(0x045e, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE), > + .driver_info = (unsigned long)&cdc_mbim_info_set_input_size_explicitly, > + }, > + > /* default entry */ > { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE), > .driver_info = (unsigned long)&cdc_mbim_info_zlp, > diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c > index 8d5cbda33f66..915e29c987cb 100644 > --- a/drivers/net/usb/cdc_ncm.c > +++ b/drivers/net/usb/cdc_ncm.c > @@ -407,7 +407,7 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx) > val = cdc_ncm_check_rx_max(dev, new_rx); > > /* inform device about NTB input size changes */ > - if (val != ctx->rx_max) { > + if (val != ctx->rx_max || ctx->drvflags & CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY) { > __le32 dwNtbInMaxSize = cpu_to_le32(val); > > dev_info(&dev->intf->dev, "setting rx_max = %u\n", val); > diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h > index 2d207cb4837d..a24f84b31a54 100644 > --- a/include/linux/usb/cdc_ncm.h > +++ b/include/linux/usb/cdc_ncm.h > @@ -88,6 +88,7 @@ > #define CDC_NCM_FLAG_NDP_TO_END 0x02 /* NDP is placed at end of frame */ > #define CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE 0x04 /* Avoid altsetting toggle during init */ > #define CDC_NCM_FLAG_PREFER_NTB32 0x08 /* prefer NDP32 over NDP16 */ > +#define CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY 0x10 /* Set input size explicitly during init */ > > #define cdc_ncm_comm_intf_is_mbim(x) ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \ > (x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE) > -- > 2.30.2 >
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c index c89639381eca..c0c23cfc02a7 100644 --- a/drivers/net/usb/cdc_mbim.c +++ b/drivers/net/usb/cdc_mbim.c @@ -618,6 +618,22 @@ static const struct driver_info cdc_mbim_info_avoid_altsetting_toggle = { .data = CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE, }; +/* Microsoft branded modems do not work properly without setting the input size + * explicitly in cdc_ncm_bind_common. + * CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY flag is used to set the input size + * during initialization. + */ +static const struct driver_info cdc_mbim_info_set_input_size_explicitly = { + .description = "CDC MBIM", + .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP, + .bind = cdc_mbim_bind, + .unbind = cdc_mbim_unbind, + .manage_power = cdc_mbim_manage_power, + .rx_fixup = cdc_mbim_rx_fixup, + .tx_fixup = cdc_mbim_tx_fixup, + .data = CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY, +}; + static const struct usb_device_id mbim_devs[] = { /* This duplicate NCM entry is intentional. MBIM devices can * be disguised as NCM by default, and this is necessary to @@ -665,6 +681,14 @@ static const struct usb_device_id mbim_devs[] = { .driver_info = (unsigned long)&cdc_mbim_info_avoid_altsetting_toggle, }, + /* Some Microsoft branded mobile broadband modems used in the Surface + * seires are known to fail unless the input size is set explicitly. + * Applying it to all Microsoft branded MBMs. + */ + { USB_VENDOR_AND_INTERFACE_INFO(0x045e, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE), + .driver_info = (unsigned long)&cdc_mbim_info_set_input_size_explicitly, + }, + /* default entry */ { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE), .driver_info = (unsigned long)&cdc_mbim_info_zlp, diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 8d5cbda33f66..915e29c987cb 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -407,7 +407,7 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx) val = cdc_ncm_check_rx_max(dev, new_rx); /* inform device about NTB input size changes */ - if (val != ctx->rx_max) { + if (val != ctx->rx_max || ctx->drvflags & CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY) { __le32 dwNtbInMaxSize = cpu_to_le32(val); dev_info(&dev->intf->dev, "setting rx_max = %u\n", val); diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h index 2d207cb4837d..a24f84b31a54 100644 --- a/include/linux/usb/cdc_ncm.h +++ b/include/linux/usb/cdc_ncm.h @@ -88,6 +88,7 @@ #define CDC_NCM_FLAG_NDP_TO_END 0x02 /* NDP is placed at end of frame */ #define CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE 0x04 /* Avoid altsetting toggle during init */ #define CDC_NCM_FLAG_PREFER_NTB32 0x08 /* prefer NDP32 over NDP16 */ +#define CDC_MBIM_FLAG_SET_INPUT_SIZE_EXPLICITLY 0x10 /* Set input size explicitly during init */ #define cdc_ncm_comm_intf_is_mbim(x) ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \ (x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE)