From 190eaf4f8d95196b1b66c7c356d28643a6355039 Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Tue, 2 Nov 2021 16:01:36 +0000 Subject: [PATCH] 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 --- drivers/gpu/drm/drm_color_mgmt.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -326,8 +326,12 @@ static int drm_crtc_legacy_gamma_set(str replaced = drm_property_replace_blob(&crtc_state->degamma_lut, use_gamma_lut ? NULL : blob); replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL); - replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, + 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, use_gamma_lut ? blob : NULL); + else + drm_property_blob_put(blob); crtc_state->color_mgmt_changed |= replaced; ret = drm_atomic_commit(state);