Re: [PATCH] drm/i915: Skip fence installation for objects with rotated views (v2)

Tvrtko Ursulin
2015-10-27T13:35:04Z

On 27/10/15 12:51, Ville Syrjälä wrote:
> On Mon, Oct 26, 2015 at 06:23:26PM -0700, Vivek Kasireddy wrote:
>> While pinning a fb object to the display plane, only install a fence
>> if the object is using a normal view. This corresponds with the
>> behavior found in i915_gem_object_do_pin() where the fencability
>> criteria is determined only for objects with normal views.
>>
>> v2:
>> Look at the object's map_and_fenceable flag to determine whether to
>> install a fence or not (Chris).
>>
>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>> Cc: Daniel Vetter <daniel@ffwll.ch>
>> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
>> ---
>> drivers/gpu/drm/i915/intel_display.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 52fb3f2..108c000 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -2357,7 +2357,8 @@ intel_pin_and_fence_fb_obj(struct drm_plane *plane,
>> * framebuffer compression. For simplicity, we always install
>> * a fence as the cost is not that onerous.
>> */
>> - ret = i915_gem_object_get_fence(obj);
>> + if (obj->map_and_fenceable)
>
> This will now get the fence and pin it for the 90/270 view as well,
> even though the fence doesn't even cover that particualr gtt mapping.

I don't follow. obj->map_and_fenceable will be true only when normal
view exists, so this avoids setting up the fence when no normal view
exists and so avoids the WARN_ON in i915_gem_object_get_fence.

Regards,

Tvrtko