Re: [PATCH] mac80211: Push idle state to driver before stop

["Luis R. Rodriguez" <lrodriguez@atheros.com>]

On Thu, Dec 16, 2010 at 08:02:27AM -0800, Paul Stewart wrote:
> On Thu, Dec 16, 2010 at 4:53 AM, Johannes Berg
> <johannes@sipsolutions.net> wrote:
> > On Thu, 2010-12-16 at 04:46 -0800, Paul Stewart wrote:
> > Not really -- the driver may throw away all internal state, mac80211
> > will (attempt to) restore it all through drv_config() with changed = ~0.
> > Evidently ath9k has some magic that makes this fail?
> 
> The magic in question is as follows (ath9k_config()):
> 
>     if (changed & IEEE80211_CONF_CHANGE_IDLE) {
>         bool enable_radio;
>         bool all_wiphys_idle;
>         bool idle = !!(conf->flags & IEEE80211_CONF_IDLE);
> 
>         spin_lock_bh(&sc->wiphy_lock);
>         all_wiphys_idle =  ath9k_all_wiphys_idle(sc);
>        ath9k_set_wiphy_idle(aphy, idle);
> 
>         enable_radio = (!idle && all_wiphys_idle);
> 
>         /*
>          * After we unlock here its possible another wiphy
>          * can be re-renabled so to account for that we will
>          * only disable the radio toward the end of this routine
>          * if by then all wiphys are still idle.
>          */
>         spin_unlock_bh(&sc->wiphy_lock);
> 
>         if (enable_radio) {
>             sc->ps_idle = false;
>             ath_radio_enable(sc, hw);
>             ath_dbg(common, ATH_DBG_CONFIG,
>                     "not-idle: enabling radio\n");
>         }
>     }
> 
> So, ath9k enables and disables the radio based on ps_idle (the
> internal state), but that's not re-evaluated unless the wiphys
> actually change.  In this case they do not change because ath9k was
> never informed that the wiphy went idle (all_wiphys_idle evaluates to
> false).  One solution would be to do an ah9k_set_wiphy_idle(aphy,
> true) in ath9k_stop() instead of Luis' previous suggestion of setting
> sc->ps_idle directly.  Perhaps in January when I return from vacation
> I'll test this to make sure that performs as intended in the
> suspend-resume-while-associated case.  It's a little bit of a lie to
> do it in this case since in fact as far as mac80211 is concerned, the
> wiphy is not idle in this case.

Try this:

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index c68205d..3de3dbf 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1350,6 +1350,7 @@ static void ath9k_stop(struct ieee80211_hw *hw)
 	ath9k_ps_restore(sc);
 
 	sc->ps_idle = true;
+	ath9k_set_wiphy_idle(aphy, true);
 	ath_radio_disable(sc, hw);
 
 	sc->sc_flags |= SC_OP_INVALID;
diff --git a/drivers/net/wireless/ath/ath9k/pci.c b/drivers/net/wireless/ath/ath9k/pci.c
index 7ca8499..4538283 100644
--- a/drivers/net/wireless/ath/ath9k/pci.c
+++ b/drivers/net/wireless/ath/ath9k/pci.c
@@ -310,6 +310,7 @@ static int ath_pci_resume(struct device *device)
 	ath9k_hw_set_gpio(sc->sc_ah, sc->sc_ah->led_pin, 1);
 
 	sc->ps_idle = true;
+	ath9k_set_wiphy_idle(aphy, true);
 	ath_radio_disable(sc, hw);
 
 	return 0;