[Intel-gfx] [PATCH 05/11] drm/i915: Check framebuffer stride more thoroughly

[ville.syrjala at linux.intel.com]

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

Make sure the the framebuffer stride is smaller than 32k. That
seems to be the limit on recent hardware. Not quite sure if
<=Gen4 has smaller limits.

Also when using a tiled memory make sure the object stride matches
the framebuffer stride.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---

I had an earlier version a long time ago that tried to use smaller stride limits
on <=Gen4, but as there isn't clear information what those limits are, I decided
to just check for the 32K limit everywhere. It's definitely an upper bound for
the older hardware as well.

 drivers/gpu/drm/i915/intel_display.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index b42637b..f431f2a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8235,6 +8235,14 @@ int intel_framebuffer_init(struct drm_device *dev,
 	if (mode_cmd->pitches[0] & 63)
 		return -EINVAL;
 
+	/* FIXME <= Gen4 stride limits are bit unclear */
+	if (mode_cmd->pitches[0] > 32768)
+		return -EINVAL;
+
+	if (obj->tiling_mode != I915_TILING_NONE &&
+	    mode_cmd->pitches[0] != obj->stride)
+		return -EINVAL;
+
 	/* Reject formats not supported by any plane early. */
 	switch (mode_cmd->pixel_format) {
 	case DRM_FORMAT_C8:
-- 
1.7.8.6