From 5e59f7175f96550ede91f58d267d2b551cb6fbba Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Mon, 30 Jun 2014 10:41:24 -0700 Subject: [PATCH] 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 Signed-off-by: Ben Widawsky Signed-off-by: Rodrigo Vivi Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_drv.h | 3 +- drivers/gpu/drm/i915/i915_gem_stolen.c | 54 +++++++++++++++++++------- drivers/gpu/drm/i915/intel_pm.c | 30 ++++++++++++-- 3 files changed, 69 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 7aeaaaabf308..07982e301b5d 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -600,6 +600,7 @@ struct intel_context { struct i915_fbc { unsigned long size; + unsigned threshold; unsigned int fb_id; enum plane plane; int y; @@ -2487,7 +2488,7 @@ static inline void i915_gem_chipset_flush(struct drm_device *dev) /* 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 * diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index a86b33193d9f..b695d184c487 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) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index cb261457bfd1..2ce96364bac7 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -229,9 +229,20 @@ static void ironlake_enable_fbc(struct drm_crtc *crtc) dpfc_ctl = DPFC_CTL_PLANE(intel_crtc->plane); if (drm_format_plane_cpp(fb->pixel_format, 0) == 2) + dev_priv->fbc.threshold++; + + switch (dev_priv->fbc.threshold) { + case 4: + case 3: + dpfc_ctl |= DPFC_CTL_LIMIT_4X; + break; + case 2: dpfc_ctl |= DPFC_CTL_LIMIT_2X; - else + break; + case 1: dpfc_ctl |= DPFC_CTL_LIMIT_1X; + break; + } dpfc_ctl |= DPFC_CTL_FENCE_EN; if (IS_GEN5(dev)) dpfc_ctl |= obj->fence_reg; @@ -285,9 +296,21 @@ static void gen7_enable_fbc(struct drm_crtc *crtc) dpfc_ctl = IVB_DPFC_CTL_PLANE(intel_crtc->plane); if (drm_format_plane_cpp(fb->pixel_format, 0) == 2) + dev_priv->fbc.threshold++; + + switch (dev_priv->fbc.threshold) { + case 4: + case 3: + dpfc_ctl |= DPFC_CTL_LIMIT_4X; + break; + case 2: dpfc_ctl |= DPFC_CTL_LIMIT_2X; - else + break; + case 1: dpfc_ctl |= DPFC_CTL_LIMIT_1X; + break; + } + dpfc_ctl |= IVB_DPFC_CTL_FENCE_EN; I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN); @@ -567,7 +590,8 @@ void intel_update_fbc(struct drm_device *dev) if (in_dbg_master()) goto out_disable; - if (i915_gem_stolen_setup_compression(dev, intel_fb->obj->base.size)) { + if (i915_gem_stolen_setup_compression(dev, intel_fb->obj->base.size, + drm_format_plane_cpp(fb->pixel_format, 0))) { if (set_no_fbc_reason(dev_priv, FBC_STOLEN_TOO_SMALL)) DRM_DEBUG_KMS("framebuffer too large, disabling compression\n"); goto out_disable; -- 2.20.1