[Intel-gfx] [PATCH 01/13] drm/atomic: Only update crtc->x/y if it's part of the state.

[Maarten Lankhorst]

Op 16-07-15 om 11:19 schreef Daniel Vetter:
> On Thu, Jul 16, 2015 at 10:59:14AM +0200, Maarten Lankhorst wrote:
>> Cc: dri-devel at lists.freedesktop.org
>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> ---
>>  drivers/gpu/drm/drm_atomic_helper.c | 7 +++++--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
>> index 0898afbc9e23..70e69904291d 100644
>> --- a/drivers/gpu/drm/drm_atomic_helper.c
>> +++ b/drivers/gpu/drm/drm_atomic_helper.c
>> @@ -667,8 +667,11 @@ drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev,
>>  	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
>>  		crtc->mode = crtc->state->mode;
>>  		crtc->enabled = crtc->state->enable;
>> -		crtc->x = crtc->primary->state->src_x >> 16;
>> -		crtc->y = crtc->primary->state->src_y >> 16;
>> +
>> +		if (drm_atomic_get_existing_plane_state(old_state, crtc->primary)) {
>> +			crtc->x = crtc->primary->state->src_x >> 16;
>> +			crtc->y = crtc->primary->state->src_y >> 16;
>> +		}
> What's the benefit here of only updating when something changed? The
> atomic state should be the master source so copying a few too many times
> shouldn't matter really.
Because you might not be holding plane lock, so primary->state may be garbage.

~Maarten