diff options
author | Ben Widawsky <benjamin.widawsky@intel.com> | 2014-06-30 10:41:24 -0700 |
---|---|---|
committer | Jani Nikula <jani.nikula@intel.com> | 2014-07-03 11:27:57 +0300 |
commit | 5e59f7175f96550ede91f58d267d2b551cb6fbba (patch) | |
tree | 01c9a04c00264d19d077880a88d43ceffdbbc854 /drivers/gpu/drm/i915/i915_gem_stolen.c | |
parent | edc0fdbbf6d8e179a0b28b9fc7597cbadabe77a8 (diff) | |
download | op-kernel-dev-5e59f7175f96550ede91f58d267d2b551cb6fbba.zip op-kernel-dev-5e59f7175f96550ede91f58d267d2b551cb6fbba.tar.gz |
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>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_stolen.c')
-rw-r--r-- | drivers/gpu/drm/i915/i915_gem_stolen.c | 54 |
1 files changed, 40 insertions, 14 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index a86b331..b695d18 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -105,35 +105,61 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev) static int find_compression_threshold(struct drm_device *dev, struct drm_mm_node *node, - int size) + int size, + int fb_cpp) { struct drm_i915_private *dev_priv = dev->dev_private; - const int compression_threshold = 1; + int compression_threshold = 1; int ret; - /* Try to over-allocate to reduce reallocations and fragmentation */ + /* HACK: This code depends on what we will do in *_enable_fbc. If that + * code changes, this code needs to change as well. + * + * The enable_fbc code will attempt to use one of our 2 compression + * thresholds, therefore, in that case, we only have 1 resort. + */ + + /* Try to over-allocate to reduce reallocations and fragmentation. */ ret = drm_mm_insert_node(&dev_priv->mm.stolen, node, size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT); - if (ret) - ret = drm_mm_insert_node(&dev_priv->mm.stolen, node, - size >>= 1, 4096, - DRM_MM_SEARCH_DEFAULT); - if (ret) + if (ret == 0) + return compression_threshold; + +again: + /* HW's ability to limit the CFB is 1:4 */ + if (compression_threshold > 4 || + (fb_cpp == 2 && compression_threshold == 2)) return 0; - else + + ret = drm_mm_insert_node(&dev_priv->mm.stolen, node, + size >>= 1, 4096, + DRM_MM_SEARCH_DEFAULT); + if (ret && INTEL_INFO(dev)->gen <= 4) { + return 0; + } else if (ret) { + compression_threshold <<= 1; + goto again; + } else { return compression_threshold; + } } -static int i915_setup_compression(struct drm_device *dev, int size) +static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp) { struct drm_i915_private *dev_priv = dev->dev_private; struct drm_mm_node *uninitialized_var(compressed_llb); int ret; ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb, - size); + size, fb_cpp); if (!ret) goto err_llb; + else if (ret > 1) { + DRM_INFO("Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.\n"); + + } + + dev_priv->fbc.threshold = ret; if (HAS_PCH_SPLIT(dev)) I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start); @@ -157,7 +183,7 @@ static int i915_setup_compression(struct drm_device *dev, int size) dev_priv->mm.stolen_base + compressed_llb->start); } - dev_priv->fbc.size = size; + dev_priv->fbc.size = size / dev_priv->fbc.threshold; DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n", size); @@ -172,7 +198,7 @@ err_llb: return -ENOSPC; } -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) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -185,7 +211,7 @@ int i915_gem_stolen_setup_compression(struct drm_device *dev, int size) /* Release any current block */ i915_gem_stolen_cleanup_compression(dev); - return i915_setup_compression(dev, size); + return i915_setup_compression(dev, size, fb_cpp); } void i915_gem_stolen_cleanup_compression(struct drm_device *dev) |