Subject: Re: [PATCH v2 1/2] ath10k: Keep track of which interrupts fired, don't poll them

From: Kalle Valo <[email-masked]>
Date: Tue, 1 Sep 2020 12:06:04 +0000 (UTC)

Douglas Anderson <[email-masked]> wrote:

> If we have a per CE (Copy Engine) IRQ then we have no summary
> register.  Right now the code generates a summary register by
> iterating over all copy engines and seeing if they have an interrupt
> pending.
> 
> This has a problem.  Specifically if _none_ if the Copy Engines have
> an interrupt pending then they might go into low power mode and
> reading from their address space will cause a full system crash.  This
> was seen to happen when two interrupts went off at nearly the same
> time.  Both were handled by a single call of ath10k_snoc_napi_poll()
> but, because there were two interrupts handled and thus two calls to
> napi_schedule() there was still a second call to
> ath10k_snoc_napi_poll() which ran with no interrupts pending.
> 
> Instead of iterating over all the copy engines, let's just keep track
> of the IRQs that fire.  Then we can effectively generate our own
> summary without ever needing to read the Copy Engines.
> 
> Tested-on: WCN3990 SNOC WLAN.HL.3.2.2-00490-QCAHLSWMTPL-1
> 
> Signed-off-by: Douglas Anderson <[email-masked]>
> Reviewed-by: Rakesh Pillai <[email-masked]>
> Reviewed-by: Brian Norris <[email-masked]>
> Signed-off-by: Kalle Valo <[email-masked]>

2 patches applied to ath-next branch of ath.git, thanks.

d66d24ac300c ath10k: Keep track of which interrupts fired, don't poll them
7f8655166512 ath10k: Get rid of "per_ce_irq" hw param

-- 
https://patchwork.kernel.org/patch/11654625/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches