Re: [PATCH 2/2] wifi: ath10k: Flush only requested txq in ath10k_flush()

[Jeff Johnson <quic_jjohnson@quicinc.com>]

On 10/12/2024 7:13 AM, Remi Pommarel wrote:
> The ieee80211 flush callback can be called to flush only part of all hw
> queues. The ath10k's flush callback implementation (i.e. ath10k_flush())
> was waiting for all pending frames of all queues to be flushed ignoring
> the queue parameter. Because only the queues to be flushed are stopped
> by mac80211, skb can still be queued to other queues meanwhile. Thus
> ath10k_flush() could fail (and wait 5sec holding ar->conf lock) even if
> the requested queues are flushed correctly.
> 
> A way to reproduce the issue is to use two different APs because
> each vdev has its own hw queue in ath10k. Connect STA0 to AP0 and STA1
> to AP1. Then generate traffic from AP0 to STA0 and kill STA0 without
> clean disassociation frame (e.g. unplug power cable, reboot -f, ...).
> Now if we were to flush AP1's queue, ath10k_flush() would fail (and
> effectively block 5 seconds with ar->conf or even wiphy's lock held)
> with the following warning:
> 
>  ath10k_pci 0000:01:00.0: failed to flush transmit queue (skip 0 ar-state 2): 0
> 
> Wait only for pending frames of the requested queues to be flushed in
> ath10k_flush() to avoid that long blocking.
> 
> Reported-by: Cedric Veilleux <veilleux.cedric@gmail.com>

WARNING:BAD_REPORTED_BY_LINK: Reported-by: should be immediately followed by Closes: with a URL to the report

> Signed-off-by: Remi Pommarel <repk@triplefau.lt>
> ---
>  drivers/net/wireless/ath/ath10k/htt.h    |  7 +++--
>  drivers/net/wireless/ath/ath10k/htt_tx.c | 18 ++++++++++---
>  drivers/net/wireless/ath/ath10k/mac.c    | 33 +++++++++++++++++-------
>  drivers/net/wireless/ath/ath10k/txrx.c   |  2 +-
>  4 files changed, 44 insertions(+), 16 deletions(-)