drm/core: Change declaration for gamma_set.

Change return value to int to propagate errors from gamma_set,
and remove start parameter. Updates always use the full size,
and some drivers even ignore the start parameter altogether.

This is needed for atomic drivers, where an atomic commit can
fail with -EINTR or -ENOMEM and should be restarted. This is already
and issue for drm_atomic_helper_legacy_set_gamma, which this patch
fixes up.

Changes since v1:
- Fix compiler warning. (Emil)
- Fix commit message (Daniel)

Cc: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Mathieu Larouche <mathieu.larouche@matrox.com>
Cc: Thierry Reding <treding@nvidia.com>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Improve commit message a bit more, mention that this fixes
the helper.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/742944bc-9f41-1acb-df4f-0fd4c8a10168@linux.intel.com

1 files changed, 6 insertions, 7 deletions

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 4342f3dfc0e1..191d84f12e67 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2920,16 +2920,15 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
  * @red: red correction table
  * @green: green correction table
  * @blue: green correction table
- * @start: first entry, must always be 0
  * @size: size of the tables
  *
  * Implements support for legacy gamma correction table for drivers
  * that support color management through the DEGAMMA_LUT/GAMMA_LUT
  * properties.
  */
-void drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
-					u16 *red, u16 *green, u16 *blue,
-					uint32_t start, uint32_t size)
+int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
+				       u16 *red, u16 *green, u16 *blue,
+				       uint32_t size)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_mode_config *config = &dev->mode_config;
@@ -2941,7 +2940,7 @@ void drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
 
 	state = drm_atomic_state_alloc(crtc->dev);
 	if (!state)
-		return;
+		return -ENOMEM;
 
 	blob = drm_property_create_blob(dev,
 					sizeof(struct drm_color_lut) * size,
@@ -2992,7 +2991,7 @@ retry:
 
 	drm_property_unreference_blob(blob);
 
-	return;
+	return 0;
 fail:
 	if (ret == -EDEADLK)
 		goto backoff;
@@ -3000,7 +2999,7 @@ fail:
 	drm_atomic_state_free(state);
 	drm_property_unreference_blob(blob);
 
-	return;
+	return ret;
 backoff:
 	drm_atomic_state_clear(state);
 	drm_atomic_legacy_backoff(state);