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

2 files changed, 7 insertions, 6 deletions

diff --git a/drivers/gpu/drm/gma500/gma_display.c b/drivers/gpu/drm/gma500/gma_display.c
index c95406e6f44d..5b636bf0b467 100644
--- a/drivers/gpu/drm/gma500/gma_display.c
+++ b/drivers/gpu/drm/gma500/gma_display.c
@@ -175,20 +175,21 @@ void gma_crtc_load_lut(struct drm_crtc *crtc)
 	}
 }
 
-void gma_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green, u16 *blue,
-			u32 start, u32 size)
+int gma_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green, u16 *blue,
+		       u32 size)
 {
 	struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
 	int i;
-	int end = (start + size > 256) ? 256 : start + size;
 
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		gma_crtc->lut_r[i] = red[i] >> 8;
 		gma_crtc->lut_g[i] = green[i] >> 8;
 		gma_crtc->lut_b[i] = blue[i] >> 8;
 	}
 
 	gma_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 /**
diff --git a/drivers/gpu/drm/gma500/gma_display.h b/drivers/gpu/drm/gma500/gma_display.h
index b2491c65f053..e72dd08b701b 100644
--- a/drivers/gpu/drm/gma500/gma_display.h
+++ b/drivers/gpu/drm/gma500/gma_display.h
@@ -72,8 +72,8 @@ extern int gma_crtc_cursor_set(struct drm_crtc *crtc,
 			       uint32_t width, uint32_t height);
 extern int gma_crtc_cursor_move(struct drm_crtc *crtc, int x, int y);
 extern void gma_crtc_load_lut(struct drm_crtc *crtc);
-extern void gma_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-			       u16 *blue, u32 start, u32 size);
+extern int gma_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+			      u16 *blue, u32 size);
 extern void gma_crtc_dpms(struct drm_crtc *crtc, int mode);
 extern void gma_crtc_prepare(struct drm_crtc *crtc);
 extern void gma_crtc_commit(struct drm_crtc *crtc);