Re: [PATCH 1/3] ath9k: fix beacon timer handling issues

[Felix Fietkau <nbd@openwrt.org>]

On 2011-03-25 3:50 AM, Sujith wrote:
> Felix Fietkau wrote:
>> AP mode beacon timers in ath9k are configured in milliseconds, which breaks
>> when increasing ATH_BCBUF to 8 instead of 4 (due to rounding errors).
>> Since the hardware timers are actually configured in microseconds, it's
>> better to let the driver use that unit directly.
>> 
>> To be able to do that, the beacon interval parameter abuse for passing
>> certain flags needs to be removed. This is easy to do, because those flags
>> are completely unnecessary anyway. ATH9K_BEACON_ENA is ignored,
>> ATH9K_BEACON_RESET_TSF can be replaced with calling ath9k_hw_reset_tsf
>> from the driver directly.
> 
> I know this has been merged, but this changes the behaviour.
> 
> Earlier, the HW TSF would be reset _after_ the beacon timers have been
> configured, but now this isn't so. Wouldn't this alter the timers ?
The HW TSF reset was still issued before the code would activate the
timers (with the write to AR_TIMER_MODE), so I don't think this changes
the behaviour of the timers.
Since the timers are scheduled for absolute TSF32 values and (in case of
a reset being issued) always set to TU_TO_USEC(intval / ATH_BCBUF), that
leaves enough time for the timers to settle in after the TSF reset, so I
don't expect any race conditions there.

- Felix