On Thu, Nov 3, 2016 at 11:59 AM, Felix Fietkau <nbd@xxxxxxxx> wrote:
> Commit c68df2e7be0c ("mac80211: allow using AP_LINK_PS with
> mac80211-generated TIM IE") introduced a logic error, where
> __sta_info_recalc_tim turns into a no-op if local->ops->set_tim is not
> set. This prevents the beacon TIM bit from being set for all drivers
> that do not implement this op (almost all of them), thus thoroughly
> essential AP mode powersave functionality.
>
> Cc: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
> Fixes: c68df2e7be0c ("mac80211: allow using AP_LINK_PS with mac80211-generated TIM IE")
> Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
> ---
> net/mac80211/sta_info.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
> index 236d47e..621734e 100644
> --- a/net/mac80211/sta_info.c
> +++ b/net/mac80211/sta_info.c
> @@ -688,7 +688,7 @@ static void __sta_info_recalc_tim(struct sta_info *sta, bool ignore_pending)
> }
>
> /* No need to do anything if the driver does all */
> - if (!local->ops->set_tim)
> + if (local->ops->set_tim)
> return;
but ... then, you'll need call to drv_set_tim below...
Apparently, we can't rely on the ops pointer to enter or not enter this flow.
