Wen Gong <wgong@xxxxxxxxxxxxxx> writes:
> When it has more than one restart_work queued meanwhile, the 2nd
> restart_work is very esay to break the 1st restart work and lead
> recovery fail.
>
> Add a ref count to allow only one restart work running untill
> device successfully recovered.
>
> Tested with QCA6174 SDIO with firmware WLAN.RMH.4.4.1-00029.
>
> Signed-off-by: Wen Gong <wgong@xxxxxxxxxxxxxx>
> ---
> drivers/net/wireless/ath/ath10k/core.c | 13 +++++++++++++
> drivers/net/wireless/ath/ath10k/core.h | 2 ++
> drivers/net/wireless/ath/ath10k/mac.c | 1 +
> 3 files changed, 16 insertions(+)
>
> diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
> index 91f131b87efc..0e31846e6c89 100644
> --- a/drivers/net/wireless/ath/ath10k/core.c
> +++ b/drivers/net/wireless/ath/ath10k/core.c
> @@ -2199,6 +2199,14 @@ static void ath10k_core_restart(struct work_struct *work)
> {
> struct ath10k *ar = container_of(work, struct ath10k, restart_work);
> int ret;
> + int restart_count;
> +
> + restart_count = atomic_add_return(1, &ar->restart_count);
> + if (restart_count > 1) {
> + ath10k_warn(ar, "can not restart, count: %d\n", restart_count);
> + atomic_dec(&ar->restart_count);
> + return;
> + }
I have been thinking a different approach for this. I think another
option is to have a function like this:
ath10k_core_firmware_crashed()
{
queue_work(ar->workqueue, &ar->restart_work);
}
In patch 1 we would convert all existing callers to call that
function instead of queue_work() directly.
In patch 2 we would add a new flag to enum ath10k_dev_flags, or maybe
should actually use existing ATH10K_FLAG_CRASH_FLUSH? Don't know yet
which one is better. Now the function would do:
ath10k_core_firmware_crashed()
{
if (test_bit(flag))
return
set_bit(flag)
queue_work(ar->workqueue, &ar->restart_work);
}
That way restart_work queue would be called only one time.
Though I'm not sure how ATH10K_STATE_WEDGED would behave after this
change, it might get broken. Ah, actually I think even this patch breaks
the WEDGED state. This firmware restart is tricky, difficult to say what
is the best approach. Michal, are you reading? :) Any ideas?
And after looking more about this patch I don't see the need for the new
ar->restart_count atomic variable. Checking for ATH10K_FLAG_CRASH_FLUSH
would do the same thing AFAICS.
And related to this, (in a separate patch) I think we should utilise
ATH10K_FLAG_CRASH_FLUSH more. For example in ath10k_wmi_cmd_send() to
not even try to send a WMI command if the flag is set. Basically all
hardware access should be disabled except what is needed to restart the
firmware.
--
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
