[Intel-gfx] [PATCH 03/11] drm/msm: Remove call to reservation_object_test_signaled_rcu before wait

[Rob Clark]

On Fri, Sep 23, 2016 at 8:55 AM, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Mon, Aug 29, 2016 at 08:08:26AM +0100, Chris Wilson wrote:
>> Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
>> timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
>> need to handle such conversion in the caller. The only challenge are
>> those callers that wish to differentiate the error code between the
>> nonblocking busy check and potentially blocking wait.
>>
>> v2: 9 is only 0 in German.
>>
>> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: Rob Clark <robdclark at gmail.com>
>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

fyi, this is in my msm-next pull-req sent last week..  (with one small
s/MSG_PREP_NOSYNC/MSM_PREP_NOSYNC/ fixup ;-))

BR,
-R


>> ---
>>  drivers/gpu/drm/msm/msm_gem.c | 22 ++++++++++------------
>>  1 file changed, 10 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
>> index 6cd4af443139..45796a88d353 100644
>> --- a/drivers/gpu/drm/msm/msm_gem.c
>> +++ b/drivers/gpu/drm/msm/msm_gem.c
>> @@ -584,18 +584,16 @@ int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op, ktime_t *timeout)
>>  {
>>       struct msm_gem_object *msm_obj = to_msm_bo(obj);
>>       bool write = !!(op & MSM_PREP_WRITE);
>> -
>> -     if (op & MSM_PREP_NOSYNC) {
>> -             if (!reservation_object_test_signaled_rcu(msm_obj->resv, write))
>> -                     return -EBUSY;
>> -     } else {
>> -             int ret;
>> -
>> -             ret = reservation_object_wait_timeout_rcu(msm_obj->resv, write,
>> -                             true, timeout_to_jiffies(timeout));
>> -             if (ret <= 0)
>> -                     return ret == 0 ? -ETIMEDOUT : ret;
>> -     }
>> +     unsigned long remain =
>> +             op & MSG_PREP_NOSYNC ? 0 : timeout_to_jiffies(timeout);
>> +     long ret;
>> +
>> +     ret = reservation_object_wait_timeout_rcu(msm_obj->resv, write,
>> +                                               true,  remain);
>> +     if (ret == 0)
>> +             return remain == 0 ? -EBUSY : -ETIMEDOUT;
>> +     else if (ret < 0)
>> +             return ret;
>>
>>       /* TODO cache maintenance */
>>
>> --
>> 2.9.3
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
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