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

[Nick Hudson <nick.hudson%gmx.co.uk@localhost>]

On 23/11/2019 14:10, sc.dying%gmail.com@localhost wrote:
> 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/.

Oops.Thanks for spotting this.

> 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.

Not sure I follow what's going on here... did you have a DWC2_DEBUG log
for the device that triggers the uaudio_chan_pintr count != size warning?

I'll commit the fixed up diff if you agree.

Thanks,
Nick