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

drivers/gpu/drm/amd/amdgpu/dce_v10_0.c

@@ -2667,19 +2667,21 @@ static void dce_v10_0_cursor_reset(struct drm_crtc *crtc)
 	}
 }
 
-static void dce_v10_0_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				    u16 *blue, uint32_t start, uint32_t size)
+static int dce_v10_0_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				    u16 *blue, uint32_t size)
 {
 	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
-	int end = (start + size > 256) ? 256 : start + size, i;
+	int i;
 
 	/* userspace palettes are always correct as is */
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		amdgpu_crtc->lut_r[i] = red[i] >> 6;
 		amdgpu_crtc->lut_g[i] = green[i] >> 6;
 		amdgpu_crtc->lut_b[i] = blue[i] >> 6;
 	}
 	dce_v10_0_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 static void dce_v10_0_crtc_destroy(struct drm_crtc *crtc)

drivers/gpu/drm/amd/amdgpu/dce_v11_0.c

@@ -2678,19 +2678,21 @@ static void dce_v11_0_cursor_reset(struct drm_crtc *crtc)
 	}
 }
 
-static void dce_v11_0_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				    u16 *blue, uint32_t start, uint32_t size)
+static int dce_v11_0_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				    u16 *blue, uint32_t size)
 {
 	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
-	int end = (start + size > 256) ? 256 : start + size, i;
+	int i;
 
 	/* userspace palettes are always correct as is */
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		amdgpu_crtc->lut_r[i] = red[i] >> 6;
 		amdgpu_crtc->lut_g[i] = green[i] >> 6;
 		amdgpu_crtc->lut_b[i] = blue[i] >> 6;
 	}
 	dce_v11_0_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 static void dce_v11_0_crtc_destroy(struct drm_crtc *crtc)

drivers/gpu/drm/amd/amdgpu/dce_v8_0.c

@@ -2574,19 +2574,21 @@ static void dce_v8_0_cursor_reset(struct drm_crtc *crtc)
 	}
 }
 
-static void dce_v8_0_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				    u16 *blue, uint32_t start, uint32_t size)
+static int dce_v8_0_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				   u16 *blue, uint32_t size)
 {
 	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
-	int end = (start + size > 256) ? 256 : start + size, i;
+	int i;
 
 	/* userspace palettes are always correct as is */
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		amdgpu_crtc->lut_r[i] = red[i] >> 6;
 		amdgpu_crtc->lut_g[i] = green[i] >> 6;
 		amdgpu_crtc->lut_b[i] = blue[i] >> 6;
 	}
 	dce_v8_0_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 static void dce_v8_0_crtc_destroy(struct drm_crtc *crtc)

drivers/gpu/drm/ast/ast_mode.c

@@ -624,19 +624,21 @@ static void ast_crtc_reset(struct drm_crtc *crtc)
 
 }
 
-static void ast_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				 u16 *blue, uint32_t start, uint32_t size)
+static int ast_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+			      u16 *blue, uint32_t size)
 {
 	struct ast_crtc *ast_crtc = to_ast_crtc(crtc);
-	int end = (start + size > 256) ? 256 : start + size, i;
+	int i;
 
 	/* userspace palettes are always correct as is */
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		ast_crtc->lut_r[i] = red[i] >> 8;
 		ast_crtc->lut_g[i] = green[i] >> 8;
 		ast_crtc->lut_b[i] = blue[i] >> 8;
 	}
 	ast_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 

drivers/gpu/drm/cirrus/cirrus_mode.c

@@ -325,18 +325,20 @@ static void cirrus_crtc_commit(struct drm_crtc *crtc)
  * use this for 8-bit mode so can't perform smooth fades on deeper modes,
  * but it's a requirement that we provide the function
  */
-static void cirrus_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				  u16 *blue, uint32_t start, uint32_t size)
+static int cirrus_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				 u16 *blue, uint32_t size)
 {
 	struct cirrus_crtc *cirrus_crtc = to_cirrus_crtc(crtc);
 	int i;
 
-	for (i = 0; i < CIRRUS_LUT_SIZE; i++) {
+	for (i = 0; i < size; i++) {
 		cirrus_crtc->lut_r[i] = red[i];
 		cirrus_crtc->lut_g[i] = green[i];
 		cirrus_crtc->lut_b[i] = blue[i];
 	}
 	cirrus_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 /* Simple cleanup function */

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);

drivers/gpu/drm/drm_crtc.c

@@ -5172,7 +5172,7 @@ int drm_mode_gamma_set_ioctl(struct drm_device *dev,
 		goto out;
 	}
 
-	crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size);
+	ret = crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, crtc->gamma_size);
 
 out:
 	drm_modeset_unlock_all(dev);

drivers/gpu/drm/drm_fb_helper.c

@@ -227,7 +227,7 @@ static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
 	g_base = r_base + crtc->gamma_size;
 	b_base = g_base + crtc->gamma_size;
 
-	crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size);
+	crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, crtc->gamma_size);
 }
 
 /**

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;
 }
 
 /**

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);

drivers/gpu/drm/mgag200/mgag200_mode.c

@@ -1344,19 +1344,20 @@ static void mga_crtc_commit(struct drm_crtc *crtc)
  * use this for 8-bit mode so can't perform smooth fades on deeper modes,
  * but it's a requirement that we provide the function
  */
-static void mga_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				  u16 *blue, uint32_t start, uint32_t size)
+static int mga_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+			      u16 *blue, uint32_t size)
 {
 	struct mga_crtc *mga_crtc = to_mga_crtc(crtc);
-	int end = (start + size > MGAG200_LUT_SIZE) ? MGAG200_LUT_SIZE : start + size;
 	int i;
 
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		mga_crtc->lut_r[i] = red[i] >> 8;
 		mga_crtc->lut_g[i] = green[i] >> 8;
 		mga_crtc->lut_b[i] = blue[i] >> 8;
 	}
 	mga_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 /* Simple cleanup function */

drivers/gpu/drm/nouveau/dispnv04/crtc.c

@@ -785,14 +785,14 @@ nv_crtc_disable(struct drm_crtc *crtc)
 	nouveau_bo_ref(NULL, &disp->image[nv_crtc->index]);
 }
 
-static void
-nv_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b, uint32_t start,
+static int
+nv_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
 		  uint32_t size)
 {
-	int end = (start + size > 256) ? 256 : start + size, i;
 	struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);
+	int i;
 
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		nv_crtc->lut.r[i] = r[i];
 		nv_crtc->lut.g[i] = g[i];
 		nv_crtc->lut.b[i] = b[i];
@@ -805,10 +805,12 @@ nv_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b, uint32_t start,
 	 */
 	if (!nv_crtc->base.primary->fb) {
 		nv_crtc->lut.depth = 0;
-		return;
+		return 0;
 	}
 
 	nv_crtc_gamma_load(crtc);
+
+	return 0;
 }
 
 static int

drivers/gpu/drm/nouveau/nv50_display.c

@@ -1346,21 +1346,22 @@ nv50_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 	return 0;
 }
 
-static void
+static int
 nv50_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
-		    uint32_t start, uint32_t size)
+		    uint32_t size)
 {
 	struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);
-	u32 end = min_t(u32, start + size, 256);
 	u32 i;
 
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		nv_crtc->lut.r[i] = r[i];
 		nv_crtc->lut.g[i] = g[i];
 		nv_crtc->lut.b[i] = b[i];
 	}
 
 	nv50_crtc_lut_load(crtc);
+
+	return 0;
 }
 
 static void

drivers/gpu/drm/radeon/radeon_display.c

@@ -231,19 +231,21 @@ void radeon_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
 	*blue = radeon_crtc->lut_b[regno] << 6;
 }
 
-static void radeon_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				  u16 *blue, uint32_t start, uint32_t size)
+static int radeon_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				 u16 *blue, uint32_t size)
 {
 	struct radeon_crtc *radeon_crtc = to_radeon_crtc(crtc);
-	int end = (start + size > 256) ? 256 : start + size, i;
+	int i;
 
 	/* userspace palettes are always correct as is */
-	for (i = start; i < end; i++) {
+	for (i = 0; i < size; i++) {
 		radeon_crtc->lut_r[i] = red[i] >> 6;
 		radeon_crtc->lut_g[i] = green[i] >> 6;
 		radeon_crtc->lut_b[i] = blue[i] >> 6;
 	}
 	radeon_crtc_load_lut(crtc);
+
+	return 0;
 }
 
 static void radeon_crtc_destroy(struct drm_crtc *crtc)
@@ -688,6 +690,7 @@ radeon_crtc_set_config(struct drm_mode_set *set)
 	pm_runtime_put_autosuspend(dev->dev);
 	return ret;
 }
+
 static const struct drm_crtc_funcs radeon_crtc_funcs = {
 	.cursor_set2 = radeon_crtc_cursor_set2,
 	.cursor_move = radeon_crtc_cursor_move,

drivers/gpu/drm/vc4/vc4_crtc.c

@@ -175,20 +175,22 @@ vc4_crtc_lut_load(struct drm_crtc *crtc)
 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_b[i]);
 }
 
-static void
+static int
 vc4_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
-		   uint32_t start, uint32_t size)
+		   uint32_t size)
 {
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 	u32 i;
 
-	for (i = start; i < start + size; i++) {
+	for (i = 0; i < size; i++) {
 		vc4_crtc->lut_r[i] = r[i] >> 8;
 		vc4_crtc->lut_g[i] = g[i] >> 8;
 		vc4_crtc->lut_b[i] = b[i] >> 8;
 	}
 
 	vc4_crtc_lut_load(crtc);
+
+	return 0;
 }
 
 static u32 vc4_get_fifo_full_level(u32 format)

drivers/gpu/drm/vmwgfx/vmwgfx_kms.c

@@ -1404,9 +1404,9 @@ static int vmw_du_update_layout(struct vmw_private *dev_priv, unsigned num,
 	return 0;
 }
 
-void vmw_du_crtc_gamma_set(struct drm_crtc *crtc,
-			   u16 *r, u16 *g, u16 *b,
-			   uint32_t start, uint32_t size)
+int vmw_du_crtc_gamma_set(struct drm_crtc *crtc,
+			  u16 *r, u16 *g, u16 *b,
+			  uint32_t size)
 {
 	struct vmw_private *dev_priv = vmw_priv(crtc->dev);
 	int i;
@@ -1418,6 +1418,8 @@ void vmw_du_crtc_gamma_set(struct drm_crtc *crtc,
 		vmw_write(dev_priv, SVGA_PALETTE_BASE + i * 3 + 1, g[i] >> 8);
 		vmw_write(dev_priv, SVGA_PALETTE_BASE + i * 3 + 2, b[i] >> 8);
 	}
+
+	return 0;
 }
 
 int vmw_du_connector_dpms(struct drm_connector *connector, int mode)

drivers/gpu/drm/vmwgfx/vmwgfx_kms.h

@@ -195,9 +195,9 @@ struct vmw_display_unit {
 void vmw_du_cleanup(struct vmw_display_unit *du);
 void vmw_du_crtc_save(struct drm_crtc *crtc);
 void vmw_du_crtc_restore(struct drm_crtc *crtc);
-void vmw_du_crtc_gamma_set(struct drm_crtc *crtc,
+int vmw_du_crtc_gamma_set(struct drm_crtc *crtc,
 			   u16 *r, u16 *g, u16 *b,
-			   uint32_t start, uint32_t size);
+			   uint32_t size);
 int vmw_du_crtc_cursor_set2(struct drm_crtc *crtc, struct drm_file *file_priv,
 			    uint32_t handle, uint32_t width, uint32_t height,
 			    int32_t hot_x, int32_t hot_y);

include/drm/drm_atomic_helper.h

@@ -147,9 +147,9 @@ void
 __drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state);
 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 					  struct drm_connector_state *state);
-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);
 
 /**
  * drm_atomic_crtc_for_each_plane - iterate over planes currently attached to CRTC

include/drm/drm_crtc.h

@@ -479,8 +479,8 @@ struct drm_crtc_funcs {
 	 * going on, which should eventually be unified to just one set of
 	 * hooks.
 	 */
-	void (*gamma_set)(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
-			  uint32_t start, uint32_t size);
+	int (*gamma_set)(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
+			 uint32_t size);
 
 	/**
 	 * @destroy: