I used kgdb. Is it ok?
channel appeared to be 0x0:
(gdb) continue
Continuing.
[Switching to Thread 315]
Breakpoint 1, cppi41_dma_channel_program (channel=0x0, packet_sz=960,
mode=0 '\000', dma_addr=2609136576, len=960)
at ../drivers/usb/musb/musb_cppi41.c:481
481 {
(gdb) bt
#0 cppi41_dma_channel_program (channel=0x0, packet_sz=960, mode=0
'\000', dma_addr=2609136576, len=960)
at ../drivers/usb/musb/musb_cppi41.c:481
#1 0xbf251570 in musb_rx_dma_iso_cppi41 (len=<optimized out>,
urb=<optimized out>, qh=<optimized out>, hw_ep=<optimized out>,
dma=<optimized out>) at ../drivers/usb/musb/musb_host.c:1569
#2 musb_rx_dma_inventra_cppi41 (len=<optimized out>, urb=<optimized
out>, qh=<optimized out>, hw_ep=<optimized out>,
dma=<optimized out>) at ../drivers/usb/musb/musb_host.c:1652
#3 musb_host_rx (musb=0xdb3e0010, epnum=<optimized out>) at
../drivers/usb/musb/musb_host.c:1969
#4 0xbf249fb4 in musb_dma_completion (musb=<optimized out>,
epnum=<optimized out>, transmit=<optimized out>)
at ../drivers/usb/musb/musb_core.c:1693
#5 0xbf258b10 in cppi41_trans_done (cppi41_channel=0xd914c3bc) at
../drivers/usb/musb/musb_cppi41.c:148
#6 0xbf258c1c in cppi41_dma_callback (private_data=<optimized out>)
at ../drivers/usb/musb/musb_cppi41.c:286
#7 0xbf229f38 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
2016-05-20 23:10 GMT+03:00 Bin Liu <b-liu@xxxxxx>:
> Hi,
>
> On Fri, May 20, 2016 at 04:32:06PM +0300, Matwey V. Kornilov wrote:
>> 2016-05-20 16:19 GMT+03:00 <matwey@xxxxxxxxxx>:
>> > Hello,
>> >
>> > I am running 4.6-rc3 on BealgeBone Black and when I try to interract
>> > with pwc webcam attached to usb port the following kernel panic
>> > happening.
>>
>> Please note, that the same is happening with 4.6.0 release.
>
> Please apply the following patch and reproduce the oops, I'd like to
> check if the oops is caused by NULL of hw_ep->in_qh.
>
> Regards,
> -Bin.
>
> ---8<-------
> diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
> index e499b86..3492c6e 100644
> --- a/drivers/usb/musb/musb_cppi41.c
> +++ b/drivers/usb/musb/musb_cppi41.c
> @@ -489,8 +489,11 @@ static int cppi41_dma_channel_program(struct dma_channel *channel,
> if (is_host_active(cppi41_channel->controller->musb)) {
> if (cppi41_channel->is_tx)
> hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
> - else
> + else {
> + if (!cppi41_channel->hw_ep->in_qh)
> + dev_err(NULL, "->in_qh is NULL\n");
> hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
> + }
> }
>
> channel->status = MUSB_DMA_STATUS_BUSY;
>
--
With best regards,
Matwey V. Kornilov.
Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia
119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382
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