From: Ville Syrjälä Date: Wed, 22 Jan 2025 15:17:52 +0000 (+0200) Subject: drm/i915: Use more optimal VTd alignment for planes X-Git-Tag: v6.15-rc1~120^2~16^2~126 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2ffa4878512d429eecffe4ef786cbf102a8b8165;p=thirdparty%2Fkernel%2Flinux.git drm/i915: Use more optimal VTd alignment for planes Depending on the platform and/or plane type we can get away with a bit less alignment in the VT-d w/a. Reduce the numbers accordingly. Note that it's not actually clear in VLV/CHV need this w/a, and if they do we don't actually know what kind of alignment is sufficient. Leave the 256k alignment in place for now, but toss in a FIXME. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20250122151755.6928-3-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/display/i9xx_plane.c b/drivers/gpu/drm/i915/display/i9xx_plane.c index 19cc34babef35..65a2eb9e92c40 100644 --- a/drivers/gpu/drm/i915/display/i9xx_plane.c +++ b/drivers/gpu/drm/i915/display/i9xx_plane.c @@ -785,6 +785,7 @@ unsigned int vlv_plane_min_alignment(struct intel_plane *plane, if (intel_plane_can_async_flip(plane, fb->modifier)) return 256 * 1024; + /* FIXME undocumented so not sure what's actually needed */ if (intel_scanout_needs_vtd_wa(i915)) return 256 * 1024; diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c index ed8e653645390..cbeea9d965174 100644 --- a/drivers/gpu/drm/i915/display/intel_cursor.c +++ b/drivers/gpu/drm/i915/display/intel_cursor.c @@ -375,7 +375,7 @@ static unsigned int i9xx_cursor_min_alignment(struct intel_plane *plane, struct drm_i915_private *i915 = to_i915(plane->base.dev); if (intel_scanout_needs_vtd_wa(i915)) - return 256 * 1024; + return 64 * 1024; return 4 * 1024; /* physical for i915/i945 */ } diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c index d63e71fe469ed..af121c720b89d 100644 --- a/drivers/gpu/drm/i915/display/intel_sprite.c +++ b/drivers/gpu/drm/i915/display/intel_sprite.c @@ -983,7 +983,7 @@ static unsigned int g4x_sprite_min_alignment(struct intel_plane *plane, struct drm_i915_private *i915 = to_i915(plane->base.dev); if (intel_scanout_needs_vtd_wa(i915)) - return 256 * 1024; + return 128 * 1024; return 4 * 1024; }