Re: retire_capture_urb: Corrected urb data len

26 Aug 2022


      On 8/26/22 12:36 PM, Takashi Iwai wrote:
...
On Fri, 26 Aug 2022 18:22:24 +0200,
Sean Anderson wrote:
...
Hi all,
I have a "FiiO DigiHug USB Audio" sound card (1852:7022) [3]. I have had
no problems with the audio, but I did notice a large number of message
like
retire_capture_urb: 4992 callbacks suppressed
in my dmesg [1]. This is caused by the "Corrected urb data len."
warning.
What exact values are shown there?
Unfortunately, as detailed below, I was unable to turn off ratelimiting.
...
The problem is that your hardware
(likely a buggy firmware) returns the unaligned size of bytes as the
data.  Maybe it's worth to replace dev_warn_ratelimited() there with
dev_warn() and take all warnings once.  Then we can see what kind of
values are delivered from the hardware.
I'll have an attempt at that next week
...
...
The patch adding this warning [2] makes it seem like
this warning should be an uncommon occurance. However, based on the
number of suppressed callbacks, this seems to be happening at a rate of
around 500 Hz.
Is this buggy hardware? Or is this a bug in the driver? Does there need
to be a quirk? Or perhaps the warning above should be a debug instead?
There is no quirk for that.  As long as the device works with that
workaround (except for messages), we can simply add a quirk to not
warn but always apply the workaround silently for such devices.
OK. I wasn't sure what the correct resolution would be.
--Sean
...
...
I'm using 5.15.0-46-generic. I know, I know; this is a vendor
kernel. However, I went through the commits for sound/usb/pcm.c and
didn't see any major differences. I also previously saw this issue on
5.4, so this probably isn't a regression.
--Sean
[1] I would have liked to post the actual message, but I was unable to
figure out how to disable ratelimiting. I tried setting
/proc/sys/kernel/printk_ratelimit to 0,
/proc/sys/kernel/printk_ratelimit_burst to 5000, and
/proc/sys/kernel/printk to 8. However, nothing seemed to have any effect
(except that the callbacks suppressed messages were disabled). I find
this very strange, given that the callbacks suppressed message uses
KERN_WARN, and so does dev_warn_ratelimited.
[2] https://lore.kernel.org/all/4B28A659.6070303@ladisch.de/T/
[3]
Device Descriptor:
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  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0         8
  idVendor           0x1852 GYROCOM C&C Co., LTD
  idProduct          0x7022 
  bcdDevice            0.01
  iManufacturer           1 FiiO
  iProduct                2 DigiHug USB Audio
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0182
    bNumInterfaces          4
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
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      bLength                 9
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        HID Device Descriptor:
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          bDescriptorType        33
          bcdHID               1.00
          bCountryCode            0 Not supported
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      bInterfaceSubClass      1 Control Device
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      iInterface              3 FiiO USB DAC-E10
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        bDescriptorType        36
        bDescriptorSubtype      1 (HEADER)
        bcdADC               1.00
        wTotalLength       0x003e
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        baInterfaceNr(1)        3
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        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             5
        wTerminalType      0x0605 SPDIF interface
        bAssocTerminal          0
        bNrChannels             2
        wChannelConfig     0x0003
          Left Front (L)
          Right Front (R)
        iChannelNames           0 
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             9
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bNrChannels             2
        wChannelConfig     0x0003
          Left Front (L)
          Right Front (R)
        iChannelNames           0 
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID             3
        wTerminalType      0x0605 SPDIF interface
        bAssocTerminal          0
        bSourceID              16
        iTerminal               0 
      AudioControl Interface Descriptor:
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        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID             7
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bSourceID               5
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                10
        bDescriptorType        36
        bDescriptorSubtype      6 (FEATURE_UNIT)
        bUnitID                16
        bSourceID               9
        bControlSize            1
        bmaControls(0)       0x01
          Mute Control
        bmaControls(1)       0x02
          Volume Control
        bmaControls(2)       0x02
          Volume Control
        iFeature                0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
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        bDescriptorType        36
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        bDelay                  0 frames
        wFormatTag         0x0001 PCM
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        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
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        bSubframeSize           2
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        tSamFreq[ 1]        16000
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        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioStreaming Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x01
            Sampling Frequency
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0002
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       2
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           7
        bDelay                  0 frames
        wFormatTag         0x0001 PCM
      AudioStreaming Interface Descriptor:
        bLength                26
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           3
        bBitResolution         24
        bSamFreqType            6 Discrete
        tSamFreq[ 0]         8000
        tSamFreq[ 1]        16000
        tSamFreq[ 2]        32000
        tSamFreq[ 3]        44100
        tSamFreq[ 4]        48000
        tSamFreq[ 5]        96000
      Endpoint Descriptor:
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        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
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          Transfer Type            Isochronous
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          Usage Type               Data
        wMaxPacketSize     0x0246  1x 582 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioStreaming Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x01
            Sampling Frequency
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0002
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
    Interface Descriptor:
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      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
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        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
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        bDelay                  0 frames
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      AudioStreaming Interface Descriptor:
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        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
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        bSubframeSize           2
        bBitResolution         16
        bSamFreqType            4 Discrete
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        tSamFreq[ 1]        44100
        tSamFreq[ 2]        48000
        tSamFreq[ 3]        96000
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        bRefresh                0
        bSynchAddress           0
        AudioStreaming Endpoint Descriptor:
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          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
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            Sampling Frequency
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      bDescriptorType         4
      bInterfaceNumber        3
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      bNumEndpoints           1
      bInterfaceClass         1 Audio
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      bInterfaceProtocol      0 
      iInterface              0 
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        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           9
        bDelay                  0 frames
        wFormatTag         0x0001 PCM
      AudioStreaming Interface Descriptor:
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        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           3
        bBitResolution         24
        bSamFreqType            4 Discrete
        tSamFreq[ 0]        32000
        tSamFreq[ 1]        44100
        tSamFreq[ 2]        48000
        tSamFreq[ 3]        96000
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        bInterval               1
        bRefresh                0
        bSynchAddress           0
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          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x01
            Sampling Frequency
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      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       3
      bNumEndpoints           1
      bInterfaceClass         1 Audio
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      iInterface              0 
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        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           9
        bDelay                  0 frames
        wFormatTag         0x2001 IEC1937_AC-3
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        bFormatType             3 (FORMAT_TYPE_III)
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          Usage Type               Data
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        bInterval               1
        bRefresh                0
        bSynchAddress           0
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          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x01
            Sampling Frequency
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          wLockDelay         0x0002
can't get debug descriptor: Resource temporarily unavailable
Device Status:     0x0000
  (Bus Powered)