Re: [PATCH] ath9k : Fix ieee80211 work while going to suspend

On Mon, Mar 18, 2013 at 02:03:08PM -0700, Luis R. Rodriguez wrote:

quoted

quoted

--- a/drivers/net/wireless/ath/ath9k/link.c
+++ b/drivers/net/wireless/ath/ath9k/link.c

@@ -158,7 +158,8 @@ void ath_start_rx_poll(struct ath_softc *sc, u8 nbeacon)
 {
  if (!AR_SREV_9300(sc->sc_ah))
  return;
-
+ if (sc->suspending)
+ return;

Thanks for the patch! Please note the style issue here, you should
use a tab, but other than that lets review what happened.

quoted

quoted

  if (!test_bit(SC_OP_PRIM_STA_VIF, &sc->sc_flags))
  return;

Note that what this will do is call later mod_timer() for
rx_poll_timer, the right thing to do then, which would
be equivalent to your patch is to modify the ath_start_rx_poll()
to instead use the new API mod_timer_pending() added on v2.6.30
via commit 74019224. This would not re-arm the timer if it was
previously removed.

[snip]

-	mod_timer(&sc->rx_poll_timer, jiffies + msecs_to_jiffies
-		  (nbeacon * sc->cur_beacon_conf.beacon_interval));
+	mod_timer_pending(&sc->rx_poll_timer, jiffies + msecs_to_jiffies
+			  (nbeacon * sc->cur_beacon_conf.beacon_interval));

But isn't this prevent to run timer in case it was not running, but
we want to start it ?

Looking at this makes me think we should review all usage of
mod_timer all over our 802.11 drivers, and mac80211, cfg80211 as
well.

I mac80211 we use local->suspended and local->quiesce booleans to
prevent reschedule of timers when going to suspend for example.
Works use ifmgd->associted to prevent reschedule when we are
disassociating.

I think on ath9k also some boolean variable should be used, not only
for rx_poll_timer but also for other works i.e. tx_complete_work.
Is possible to use SC_OP_INVALID flags, since mac80211 call ath9k_stop
on suspend and ath9k_start on resume.

Stanislaw