[PATCH] ALSA: usb-audio: allow -EPIPE errors for some v2 messages

[Takashi Iwai]

On Mon, 11 Oct 2021 17:28:15 +0200,
Greg Kroah-Hartman wrote:
> 
> On Sun, Oct 10, 2021 at 10:25:09PM +0200, Takashi Iwai wrote:
> > On Sun, 10 Oct 2021 14:22:41 +0200,
> > Greg Kroah-Hartman wrote:
> > > 
> > > The Schiit Hel device does not like to respond to all get_ctl_value_v2()
> > > requests for some reason.  This used to work in older kernels, but now
> > > with more strict checking, this failure causes the device to fail to
> > > work.
> > > 
> > > Cc: Jaroslav Kysela <perex at perex.cz>
> > > Cc: Takashi Iwai <tiwai at suse.com>
> > > Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> > > ---
> > > 
> > > This fixes the Shiit Hel device that I have.  It used to work on older
> > > kernels (a year ago?), but stopped working for some reason and I didn't
> > > take the time to track it down.  This change fixes the issue for me, but
> > > feels wrong for some reason.  At least now I can use the device as a
> > > headphone driver, much better than the built-in one for my current
> > > machine...
> > > 
> > > If needed, I can take the time to do bisection to track down the real
> > > issue here, it might be due to stricter endpoint checking in the USB
> > > core, but that feels wrong somehow.
> > > 
> > > Here's the debugfs USB output for this device, showing the endpoints:
> > > 
> > > T:  Bus=07 Lev=02 Prnt=02 Port=01 Cnt=01 Dev#=  5 Spd=480 MxCh= 0
> > > D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
> > > P:  Vendor=30be ProdID=0101 Rev=01.02
> > > S:  Manufacturer=Schiit Audio
> > > S:  Product=Schiit Hel
> > > C:  #Ifs= 4 Cfg#= 1 Atr=c0 MxPwr=0mA
> > > I:  If#= 0 Alt= 0 #EPs= 1 Cls=01(audio) Sub=01 Prot=20 Driver=snd-usb-audio
> > > E:  Ad=8f(I) Atr=03(Int.) MxPS=   6 Ivl=1ms
> > > I:  If#= 1 Alt= 1 #EPs= 2 Cls=01(audio) Sub=02 Prot=20 Driver=snd-usb-audio
> > > E:  Ad=05(O) Atr=05(Isoc) MxPS= 104 Ivl=125us
> > > E:  Ad=85(I) Atr=11(Isoc) MxPS=   4 Ivl=1ms
> > > I:  If#= 2 Alt= 1 #EPs= 1 Cls=01(audio) Sub=02 Prot=20 Driver=snd-usb-audio
> > > E:  Ad=88(I) Atr=05(Isoc) MxPS= 156 Ivl=125us
> > > I:  If#= 3 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=00 Prot=00 Driver=usbhid
> > > E:  Ad=84(I) Atr=03(Int.) MxPS=  16 Ivl=1ms
> > > 
> > > Any other suggestions to fix this are welcome.
> > 
> > Could you show the exact error messages and lsusb -v output?
> > We may paper over only the problematic node instead.
> 
> Sure, here's the dmesg output on 5.15-rc5 when it is turned on:
> 
> [Oct11 17:25] usb 7-2.2: new high-speed USB device number 9 using xhci_hcd
> [  +0.122422] usb 7-2.2: New USB device found, idVendor=30be, idProduct=0101, bcdDevice= 1.02
> [  +0.000009] usb 7-2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> [  +0.000002] usb 7-2.2: Product: Schiit Hel
> [  +0.000002] usb 7-2.2: Manufacturer: Schiit Audio
> [  +0.327172] input: Schiit Audio Schiit Hel as /devices/pci0000:40/0000:40:01.1/0000:41:00.0/0000:42:08.0/0000:47:00.1/usb7/7-2/7-2.2/7-2.2:1.3/0003:30BE:0101.0009/input/input21
> [  +0.055134] hid-generic 0003:30BE:0101.0009: input,hidraw8: USB HID v1.00 Device [Schiit Audio Schiit Hel] on usb-0000:47:00.1-2.2/input3
> [  +0.135988] usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1
> [  +0.060647] usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1
> [  +0.065362] usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1
> [  +0.192121] usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1

Thanks.  So this happens at the unit 17, and ...


> And here is the 'lsusb -v' output of the device.
> 
> 
> Bus 007 Device 009: ID 30be:0101 Schiit Audio Schiit Hel
(snip)
>       AudioControl Interface Descriptor:
>         bLength                18
>         bDescriptorType        36
>         bDescriptorSubtype      6 (FEATURE_UNIT)
>         bUnitID                17
>         bSourceID               5
>         bmaControls(0)     0x00000003
>           Mute Control (read/write)
>         bmaControls(1)     0x00000000
>         bmaControls(2)     0x00000000
>         iFeature                0 

... this is the entry.

Could you also post the contents of /proc/asound/card*/usbmixer (only
for the corresponding device), too?


thanks,

Takashi