Re: port-evbarm/54696: Kernel panic in bus_dma.c on Raspberry Pi 3B/3B+

[sc.dying%gmail.com@localhost]

On 2019/11/23 10:25, Nick Hudson wrote:
> On 14/11/2019 22:35, sc.dying%gmail.com@localhost wrote:
> [snip]
> 
>>   But the transfer length of isoc xfer is sum of xfer->ux_frlengths[i]
>>   where i = 0.. xfer->ux_nframes - 1, not zero.
>>   dwc2 should do this usb_syncmem if xfertype == UE_{INTERRUPT,BULK},
>>   UE_CONTROL that has data phase (that is, len != 0), or if xfertype ==
>>   UE_ISOCHRONOUS, should do usb_syncmem for each chunk of ux_frlengths.
>>
>>   However, the uaudio works with dwc2 even if avobe usb_syncmem is ignored.
>>   I think dwc2 does usb_syncmem for isoc data buf somewhere else, but
>>   I'm not sure where it is.
> 
> Please try this patch

I did s/ux_ux_nframes/ux_nframes/.

It works with one of my uaudio devices.

# audiocfg list
0: [*] audio0 @ uaudio0: USB audio
       playback: 2ch, 44100Hz
       record:   2ch, 44100Hz
       (-R) slinear_le 16/16, 2ch, { 44100 }
       (P-) slinear_le 16/16, 2ch, { 44100 }

With another one

0: [*] audio0 @ uaudio0: USB audio
       playback: 2ch, 48000Hz
       record:   unavailable
       (P-) slinear_le 16/16, 2ch, { 48000, 44100 }

the kernel prints number of messages, as David reported.

> uaudio_chan_pintr: count(40) != size(1920)

The length of each chunk in this transfer is
48000(kHz) x 2(bytes/chan) x 2(chans) / 1000(frames/s) = 192.
dwc2_get_actual_xfer_length() should return 192, but 4.
nframes is 10, so ux_length is 40.

If !DIAGNOSTIC, this messages are suppresssed and the kernel
plays music clearly.


> 
> thanks,
> Nick