imx-drm plane, build warning, and error handling fixes

- some fixes for active plane reconfiguration support
 - hide unused label in case of disabled CONFIG_DRM_FBDEV_EMULATION,
   which caused a build warning
 - fixed error handling in imx_drm_bind
 - disallow odd x/y plane offsets for chroma subsampled formats
 - disable local alpha when switching from a format with alpha
   channel to an opaque format
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Merge tag 'imx-drm-fixes-20161021' of git://git.pengutronix.de/pza/linux into drm-fixes

imx-drm plane, build warning, and error handling fixes

- some fixes for active plane reconfiguration support
- hide unused label in case of disabled CONFIG_DRM_FBDEV_EMULATION,
  which caused a build warning
- fixed error handling in imx_drm_bind
- disallow odd x/y plane offsets for chroma subsampled formats
- disable local alpha when switching from a format with alpha
  channel to an opaque format

* tag 'imx-drm-fixes-20161021' of git://git.pengutronix.de/pza/linux:
  drm/imx: ipuv3-plane: disable local alpha for planes without alpha channel
  drm/imx: ipuv3-plane: make sure x/y offsets are even in case of chroma subsampling
  drm/imx: ipuv3-plane: Access old u/vbo properly in ->atomic_check for YU12/YV12
  drm/imx: drm_dev_alloc() returns error pointers
  drm/imx: ipuv3-plane: Skip setting u/vbo only when we don't need modeset
  drm/imx: ipuv3-plane: Switch EBA buffer only when we don't need modeset
  gpu: ipu-v3: Use ERR_CAST instead of ERR_PTR(PTR_ERR())
  drm/imx: hide an unused label

drivers/gpu/drm/imx/imx-drm-core.c

@@ -357,8 +357,8 @@ static int imx_drm_bind(struct device *dev)
 	int ret;
 
 	drm = drm_dev_alloc(&imx_drm_driver, dev);
-	if (!drm)
-		return -ENOMEM;
+	if (IS_ERR(drm))
+		return PTR_ERR(drm);
 
 	imxdrm = devm_kzalloc(dev, sizeof(*imxdrm), GFP_KERNEL);
 	if (!imxdrm) {
@@ -436,9 +436,11 @@ static int imx_drm_bind(struct device *dev)
 
 err_fbhelper:
 	drm_kms_helper_poll_fini(drm);
+#if IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION)
 	if (imxdrm->fbhelper)
 		drm_fbdev_cma_fini(imxdrm->fbhelper);
 err_unbind:
+#endif
 	component_unbind_all(drm->dev, drm);
 err_vblank:
 	drm_vblank_cleanup(drm);

drivers/gpu/drm/imx/ipuv3-plane.c

@@ -103,11 +103,11 @@ drm_plane_state_to_vbo(struct drm_plane_state *state)
 	       (state->src_x >> 16) / 2 - eba;
 }
 
-static void ipu_plane_atomic_set_base(struct ipu_plane *ipu_plane,
-				      struct drm_plane_state *old_state)
+static void ipu_plane_atomic_set_base(struct ipu_plane *ipu_plane)
 {
 	struct drm_plane *plane = &ipu_plane->base;
 	struct drm_plane_state *state = plane->state;
+	struct drm_crtc_state *crtc_state = state->crtc->state;
 	struct drm_framebuffer *fb = state->fb;
 	unsigned long eba, ubo, vbo;
 	int active;
@@ -117,7 +117,7 @@ static void ipu_plane_atomic_set_base(struct ipu_plane *ipu_plane,
 	switch (fb->pixel_format) {
 	case DRM_FORMAT_YUV420:
 	case DRM_FORMAT_YVU420:
-		if (old_state->fb)
+		if (!drm_atomic_crtc_needs_modeset(crtc_state))
 			break;
 
 		/*
@@ -149,7 +149,7 @@ static void ipu_plane_atomic_set_base(struct ipu_plane *ipu_plane,
 		break;
 	}
 
-	if (old_state->fb) {
+	if (!drm_atomic_crtc_needs_modeset(crtc_state)) {
 		active = ipu_idmac_get_current_buffer(ipu_plane->ipu_ch);
 		ipu_cpmem_set_buffer(ipu_plane->ipu_ch, !active, eba);
 		ipu_idmac_select_buffer(ipu_plane->ipu_ch, !active);
@@ -259,6 +259,7 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
 	struct drm_framebuffer *fb = state->fb;
 	struct drm_framebuffer *old_fb = old_state->fb;
 	unsigned long eba, ubo, vbo, old_ubo, old_vbo;
+	int hsub, vsub;
 
 	/* Ok to disable */
 	if (!fb)
@@ -355,7 +356,9 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
 		if ((ubo > 0xfffff8) || (vbo > 0xfffff8))
 			return -EINVAL;
 
-		if (old_fb) {
+		if (old_fb &&
+		    (old_fb->pixel_format == DRM_FORMAT_YUV420 ||
+		     old_fb->pixel_format == DRM_FORMAT_YVU420)) {
 			old_ubo = drm_plane_state_to_ubo(old_state);
 			old_vbo = drm_plane_state_to_vbo(old_state);
 			if (ubo != old_ubo || vbo != old_vbo)
@@ -370,6 +373,16 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
 
 		if (old_fb && old_fb->pitches[1] != fb->pitches[1])
 			crtc_state->mode_changed = true;
+
+		/*
+		 * The x/y offsets must be even in case of horizontal/vertical
+		 * chroma subsampling.
+		 */
+		hsub = drm_format_horz_chroma_subsampling(fb->pixel_format);
+		vsub = drm_format_vert_chroma_subsampling(fb->pixel_format);
+		if (((state->src_x >> 16) & (hsub - 1)) ||
+		    ((state->src_y >> 16) & (vsub - 1)))
+			return -EINVAL;
 	}
 
 	return 0;
@@ -392,7 +405,7 @@ static void ipu_plane_atomic_update(struct drm_plane *plane,
 		struct drm_crtc_state *crtc_state = state->crtc->state;
 
 		if (!drm_atomic_crtc_needs_modeset(crtc_state)) {
-			ipu_plane_atomic_set_base(ipu_plane, old_state);
+			ipu_plane_atomic_set_base(ipu_plane);
 			return;
 		}
 	}
@@ -424,6 +437,7 @@ static void ipu_plane_atomic_update(struct drm_plane *plane,
 			ipu_dp_set_global_alpha(ipu_plane->dp, false, 0, false);
 			break;
 		default:
+			ipu_dp_set_global_alpha(ipu_plane->dp, true, 0, true);
 			break;
 		}
 	}
@@ -437,7 +451,7 @@ static void ipu_plane_atomic_update(struct drm_plane *plane,
 	ipu_cpmem_set_high_priority(ipu_plane->ipu_ch);
 	ipu_idmac_set_double_buffer(ipu_plane->ipu_ch, 1);
 	ipu_cpmem_set_stride(ipu_plane->ipu_ch, state->fb->pitches[0]);
-	ipu_plane_atomic_set_base(ipu_plane, old_state);
+	ipu_plane_atomic_set_base(ipu_plane);
 	ipu_plane_enable(ipu_plane);
 }
 

drivers/gpu/ipu-v3/ipu-image-convert.c

@@ -1617,7 +1617,7 @@ ipu_image_convert(struct ipu_soc *ipu, enum ipu_ic_task ic_task,
 	ctx = ipu_image_convert_prepare(ipu, ic_task, in, out, rot_mode,
 					complete, complete_context);
 	if (IS_ERR(ctx))
-		return ERR_PTR(PTR_ERR(ctx));
+		return ERR_CAST(ctx);
 
 	run = kzalloc(sizeof(*run), GFP_KERNEL);
 	if (!run) {