openwrt/target/linux/bcm27xx/patches-5.15/950-0562-drm-Check-whether-the-gamma-lut-has-changed-before-u.patch
Álvaro Fernández Rojas 20ea6adbf1 bcm27xx: add support for linux v5.15
Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2022-05-17 15:11:22 +02:00

34 lines
1.3 KiB
Diff

From 190eaf4f8d95196b1b66c7c356d28643a6355039 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
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 <dave.stevenson@raspberrypi.com>
---
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);