drm: Check whether the gamma lut has changed before updating

drm_crtc_legacy_gamma_set updates the gamma_lut blob unconditionally,
which leads to unnecessary reprogramming of hardware.

Check whether the blob contents has actually changed before
signalling that it has been updated.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
This commit is contained in:
Dave Stevenson
2021-11-02 16:01:36 +00:00
committed by Phil Elwell
parent 4ae4769d1c
commit 9cca26674a

View File

@@ -313,7 +313,11 @@ static int drm_crtc_legacy_gamma_set(struct drm_crtc *crtc,
/* Set GAMMA_LUT and reset DEGAMMA_LUT and CTM */ /* Set GAMMA_LUT and reset DEGAMMA_LUT and CTM */
replaced = drm_property_replace_blob(&crtc_state->degamma_lut, NULL); replaced = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL); replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob); if (!crtc_state->gamma_lut || !crtc_state->gamma_lut->data ||
memcmp(crtc_state->gamma_lut->data, blob_data, blob->length))
replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
else
drm_property_blob_put(blob);
crtc_state->color_mgmt_changed |= replaced; crtc_state->color_mgmt_changed |= replaced;
ret = drm_atomic_commit(state); ret = drm_atomic_commit(state);