[Mesa-dev] [PATCH 1/5] glx/dri3: Fix glXWaitForSbcOML() to handle targetSBC==0 correctly.

[Axel Davy]

Le 04/12/2014 11:44, Axel Davy a écrit :
> On 02/12/2014 20:53, Mario Kleiner wrote :
>> targetSBC == 0 is a special case, which asks the function
>> to block until all pending OpenGL bufferswap requests have
>> completed.
>>
>> Currently the function just falls through for targetSBC == 0,
>> returning bogus results.
>>
>> This breaks applications originally written and tested against
>> DRI2 which also rely on this not regressing under DRI3/Present,
>> e.g., Neuro-Science software like Psychtoolbox-3.
>>
>> This patch fixes the problem.
>>
>> Cc: "10.3 10.4" <mesa-stable at lists.freedesktop.org>
>> Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
>> ---
>>   src/glx/dri3_glx.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c
>> index a9ff73b..b4ac278 100644
>> --- a/src/glx/dri3_glx.c
>> +++ b/src/glx/dri3_glx.c
>> @@ -529,7 +529,8 @@ dri3_wait_for_sbc(__GLXDRIdrawable *pdraw, 
>> int64_t target_sbc, int64_t *ust,
>>   {
>>      struct dri3_drawable *priv = (struct dri3_drawable *) pdraw;
>>   -   while (priv->recv_sbc < target_sbc) {
>> +   while ((target_sbc != 0 && priv->recv_sbc < target_sbc) ||
>> +          (target_sbc == 0 && priv->recv_sbc < priv->send_sbc)) {
>>         if (!dri3_wait_for_event(pdraw))
>>            return 0;
>>      }
> Looks good to me.
>
> Reviewed-by: Axel Davy <axel.davy at ens.fr>
> _______________________________________________
>
Just an additional thought:

it would probably better to do instead:

if (!target_sbc)
     target_sbc = priv->send_sbc;