2016-05-21 6:13 GMT+03:00 Bin Liu <binmlist@xxxxxxxxx>:
> Hi,
>
> On Fri, May 20, 2016 at 4:20 PM, Matwey V. Kornilov <matwey@xxxxxxxxxx> wrote:
>> 2016-05-21 0:12 GMT+03:00 Bin Liu <b-liu@xxxxxx>:
>>> Hi,
>>>
>>> On Sat, May 21, 2016 at 12:05:06AM +0300, Matwey V. Kornilov wrote:
>>>> By the way, is it ok that function musb_rx_dma_iso_cppi41 uses
>>>> hw_ep->tx_channel? I would suppose that it should use rx_channel
>>>> instead.
>>>
>>> I just got here, and am wondering the same. But the question is why just
>>> your case hit the problem. I will try to look at it more next week.
>>>
>>> I had an impression the linux-usb@ has a discussion before about
>>> rx/tx-channel messing up, will have to look it up.
>>>
>>
>> Thank you.
>> If you need additional info, I can use kgdb with this issue.
>
> After reviewed the code, it must be hw_ep->rx_channel instead. It is likely a
> bug caused by commit 069a3fd (usb: musb: Remove ifdefs for musb_host_rx
> in musb_host.c part1). Please test with the following patch.
>
I've just tested this patch. Indeed, it helps to avoid kernel panic.
Now, I can interact with my webcam and watch video-stream in xawtv.
It would be great if the patch could become a part of 4.6.x stable tree.
> Regards,
> -Bin.
>
> -----8<---------
> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> index 2f8ad7f..9b2553c 100644
> --- a/drivers/usb/musb/musb_host.c
> +++ b/drivers/usb/musb/musb_host.c
> @@ -1551,7 +1551,7 @@ static int musb_rx_dma_iso_cppi41(struct
> dma_controller *dma,
> struct urb *urb,
> size_t len)
> {
> - struct dma_channel *channel = hw_ep->tx_channel;
> + struct dma_channel *channel = hw_ep->rx_channel;
> void __iomem *epio = hw_ep->regs;
> dma_addr_t *buf;
> u32 length, res;
>
--
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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