On Thu, Dec 16, 2010 at 4:53 AM, Johannes Berg
<johannes@xxxxxxxxxxxxxxxx> 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.
--
Paul
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