[Intel-gfx] [PATCH v2 18/18] drm/i915: Make sure fb offset is (macro)pixel aligned

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

We convert the fb->offsets[] into x/y offsets, so they must be
(macro)pixel aligned. Check for this, and if things look good
allow fb->offsets[] != 0 when creating fbs since we now handle
them correctly.

v2: Move to last place in the series and improve the commit message

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch> (v1)
---
 drivers/gpu/drm/i915/intel_display.c | 37 +++++++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2e6cbf65b265..0538846ad20d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14909,6 +14909,37 @@ u32 intel_fb_pitch_limit(struct drm_device *dev, uint64_t fb_modifier,
 	}
 }
 
+static int intel_fb_check_offsets(const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	uint32_t format = mode_cmd->pixel_format;
+	int num_planes = drm_format_num_planes(format);
+	int i;
+
+	for (i = 0; i < num_planes; i++) {
+		unsigned int cpp;
+
+		switch (format) {
+		case DRM_FORMAT_YUYV:
+		case DRM_FORMAT_UYVY:
+		case DRM_FORMAT_YVYU:
+		case DRM_FORMAT_VYUY:
+			cpp = 4;
+			break;
+		default:
+			cpp = drm_format_plane_cpp(format, i);
+			break;
+		}
+
+		if (mode_cmd->offsets[i] % cpp) {
+			DRM_DEBUG("fb plane %d offset 0x%08x not (macro)pixel aligned\n",
+				  i, mode_cmd->offsets[i]);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 static int intel_framebuffer_init(struct drm_device *dev,
 				  struct intel_framebuffer *intel_fb,
 				  struct drm_mode_fb_cmd2 *mode_cmd,
@@ -15035,9 +15066,9 @@ static int intel_framebuffer_init(struct drm_device *dev,
 		return -EINVAL;
 	}
 
-	/* FIXME need to adjust LINOFF/TILEOFF accordingly. */
-	if (mode_cmd->offsets[0] != 0)
-		return -EINVAL;
+	ret = intel_fb_check_offsets(mode_cmd);
+	if (ret)
+		return ret;
 
 	drm_helper_mode_fill_fb_struct(&intel_fb->base, mode_cmd);
 	intel_fb->obj = obj;
-- 
2.4.10