Re: [PATCH v2] ath10k: add flag to protect napi operation to avoid dead loop hang for SDIO

[Wen Gong <wgong@codeaurora.org>]

On 2020-08-24 18:03, Krishna Chaitanya wrote:
> On Mon, Aug 24, 2020 at 3:10 PM Wen Gong <wgong@codeaurora.org> wrote:
>> 
>> On 2020-08-24 16:35, Krishna Chaitanya wrote:
>> > On Mon, Aug 24, 2020 at 10:03 AM Wen Gong <wgong@codeaurora.org> wrote:
>> >>
>> >> It happened "Kernel panic - not syncing: hung_task: blocked tasks"
>> >> when
>> >> test simulate crash and ifconfig down/rmmod meanwhile.
>> >>
>> ...
>> >>
>> >>  #ifdef CONFIG_PM
>> > Even though your DUT is SDIO based we should be doing this in general
>> > for all, no?
>> > core_restart + hif_stop is common to all.
>> this patch does not have core_restart.
> I was referring to the combination which is causing the issue.
> 
>> I dit not hit the issue for others bus(PCIe,SNOC...), so I can not
>> change them with a
>> assumption they also have this issue.
> But that doesn't make sense, the combination is being hit for others 
> also.
> (they should also endup calling napi_disable twice?) or they are using
> some other check to avoid this (doesn't appear so from a quick look at 
> the
> code).
Because I only use SDIO, I did not use others BUS, so I did not hit the 
issue
on other BUS.
> 
> So, I am back to my initial guess that the SDIO specific async_rx_work 
> is
> causing/aggravating this issue.
the commit log of this patch has explain the reason, it is not caused by 
the
async_rx_work and I have started the "ath10k: cancel rx worker in 
hif_stop for SDIO"
for async_rx_work.