Commit 488dd075 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/i915/dsb: Fix DSB command buffer size checks 



free_pos is in dwords, DSB_BUF_SIZE in bytes. Directly
comparing the two is nonsense. Fix it up, and make sure
we also account for the 8byte alignment requirement for
each instruction, and also assume that each instruction
normally eats two dwords.

Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221216003810.13338-5-ville.syrjala@linux.intel.com


Reviewed-by: default avatarAnimesh Manna <animesh.manna@intel.com>
parent 3229319e

drivers/gpu/drm/i915/display/intel_dsb.c

+2 −2
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ void intel_dsb_indexed_reg_write(struct intel_dsb *dsb, 
	u32 *buf = dsb->cmd_buf;

	u32 reg_val;



	if (drm_WARN_ON(&dev_priv->drm, dsb->free_pos >= DSB_BUF_SIZE)) {

	if (drm_WARN_ON(&dev_priv->drm, ALIGN(dsb->free_pos, 2) > DSB_BUF_SIZE / 4 - 2)) {

		drm_dbg_kms(&dev_priv->drm, "DSB buffer overflow\n");

		return;

	}
@@ -167,7 +167,7 @@ void intel_dsb_reg_write(struct intel_dsb *dsb, 
	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);

	u32 *buf = dsb->cmd_buf;



	if (drm_WARN_ON(&dev_priv->drm, dsb->free_pos >= DSB_BUF_SIZE)) {

	if (drm_WARN_ON(&dev_priv->drm, ALIGN(dsb->free_pos, 2) > DSB_BUF_SIZE / 4 - 2)) {

		drm_dbg_kms(&dev_priv->drm, "DSB buffer overflow\n");

		return;

	}