drm/i915: Try harder to get FBC
The GEN FBC unit provides the ability to set a low pass on frames it
attempts to compress. If a frame is less than a certain amount
compressibility (2:1, 4:1) it will not bother. This allows the driver to
reduce the size it requests out of stolen memory.
Unluckily, a few months ago, Ville actually began using this feature for
framebuffers that are 16bpp (not sure why not 8bpp). In those cases, we
are already using this mechanism for a different purpose, and so we can
only achieve one further level of compression (2:1 -> 4:1)
FBC GEN1, ie. pre-G45 is ignored.
The cleverness of the patch is Art's. The bugs are mine.
v2: Update message and including missing threshold case 3 (Spotted by Arthur).
Cc: Art Runyan <arthur.j.runyan@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7aeaaaa..07982e3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -600,6 +600,7 @@
struct i915_fbc {
unsigned long size;
+ unsigned threshold;
unsigned int fb_id;
enum plane plane;
int y;
@@ -2487,7 +2488,7 @@
/* i915_gem_stolen.c */
int i915_gem_init_stolen(struct drm_device *dev);
-int i915_gem_stolen_setup_compression(struct drm_device *dev, int size);
+int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp);
void i915_gem_stolen_cleanup_compression(struct drm_device *dev);
void i915_gem_cleanup_stolen(struct drm_device *dev);
struct drm_i915_gem_object *