[Intel-gfx] [PATCH] drm/i915: Try harder to get FBC
Jani Nikula
jani.nikula at intel.com
Thu Jul 3 13:52:07 CEST 2014
On Tue, 01 Jul 2014, Rodrigo Vivi <rodrigo.vivi at gmail.com> wrote:
> Jani, please ignore the 4th patch on this series and merge the 3 I've
> reviewed and tested already.
Patches 1-3 pushed to dinq. Thanks for the patches and review.
BR,
Jani.
>
> They are essential to allow FBC work on BDW without changing bios
> configuration and allow PC7 residency.
>
> Thanks,
> Rodrigo.
>
>
> On Mon, Jun 30, 2014 at 10:41 AM, Rodrigo Vivi <rodrigo.vivi at intel.com>
> wrote:
>
>> From: Ben Widawsky <benjamin.widawsky at intel.com>
>>
>> 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).
>>
>> Reviewedby: Rodrigo Vivi <rodrigo.vivi at intel.com>
>> Cc: Art Runyan <arthur.j.runyan at intel.com>
>> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
>> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
>> ---
>> 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 5b7aed2..9953ea8 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;
>> @@ -2489,7 +2490,7 @@ 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 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)
>> diff --git a/drivers/gpu/drm/i915/intel_pm.c
>> b/drivers/gpu/drm/i915/intel_pm.c
>> index a90fdbd..4fcb2f7 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);
>> @@ -566,7 +589,8 @@ 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;
>> --
>> 1.9.1
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>>
>
>
>
> --
> Rodrigo Vivi
> Blog: http://blog.vivi.eng.br
--
Jani Nikula, Intel Open Source Technology Center
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