On 2020-08-15 01:19, Kalle Valo wrote:
Wen Gong <wgong@xxxxxxxxxxxxxx> writes:
...
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.
This is not muti-thread-safe, for example, if 2 thread entered to the
test_bit(flag) meanwhile
and both check pass, then it will have 2 restart.
atomic_add_return is muti-thread-safe, if 2 thread entered it, only 1
thread can pass
the check, another will fail and return.
The "payload length exceeds max htc length for sdio" happened many times
in a very short time,
so I add this check for it.
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.
