RE: [PATCH] usb: dwc3: gadget: fix miss isoc issue introduced by IRQ latency

From: Zengtao (B)
Date: Fri Dec 14 2018 - 04:12:09 EST


>-----Original Message-----
>From: Felipe Balbi [mailto:balbi@xxxxxxxxxx]
>Sent: Friday, December 14, 2018 4:52 PM
>To: Zengtao (B) <prime.zeng@xxxxxxxxxxxxx>
>Cc: liangshengjun <liangshengjun@xxxxxxxxxxxxx>; Zengtao (B)
><prime.zeng@xxxxxxxxxxxxx>; Greg Kroah-Hartman
><gregkh@xxxxxxxxxxxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx;
>linux-kernel@xxxxxxxxxxxxxxx
>Subject: Re: [PATCH] usb: dwc3: gadget: fix miss isoc issue introduced by
>IRQ latency
>
>* PGP Signed by an unknown key
>
>Zeng Tao <prime.zeng@xxxxxxxxxxxxx> writes:
>
>> If it's a busy system, some times when we start an isoc transfer, the
>> framenumber get from the event buffer may be already elasped, in this
>> case, we will get all the packets dropped due to miss isoc. And we
>> turn into transfer nothing, to fix this issue, we need to fix the
>> framenumber to make sure that it's not out of date.
>>
>> Signed-off-by: Liang Shengjun <liangshengjun@xxxxxxxxxxxxx>
>> Signed-off-by: Zeng Tao <prime.zeng@xxxxxxxxxxxxx>
>
>There's a patch going upstream already doing this:
>
>https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git/commit/?h
>=next&id=d53701067f048b8b11635e964b6d3bd9a248c622
>

Sorry, I think I missed to update to the latest version. But I think my
patch is more efficient. Because I just sync the frame from the HW, it
won't fail and there is no need to extra tries.

What do you think about it?

Regards
Zengtao
>--
>balbi
>
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