Attachment 48840 Details for Bug 33487 – Disable FBC upon page-flip

[patch] Disable FBC upon page-flip

0001-drm-i915-Disable-FBC-across-page-flipping.patch (text/plain), 1.88 KB, created by Chris Wilson on 2011-07-06 23:58:39 UTC

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Creator: Chris Wilson

Created: 2011-07-06 23:58:39 UTC

Size: 1.88 KB

patch

obsolete

>From 850ee0f1539d50d7d0a2132e3081adac84e92013 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Thu, 7 Jul 2011 07:51:43 +0100
>Subject: [PATCH] drm/i915: Disable FBC across page-flipping
>
>Page-flipping updates the scanout address and nukes the FBC compressed
>image and forces an update so that the displayed image remains
>consistent. However, page-flipping does not update the FBC registers
>themselves, which remain pointing to both the old address and the old
>CPU fence!
>
>This first approach to demonstrate the issue, simply disables FBC upon
>page-flip (a recompression will be forced on every flip so FBC becomes
>immaterial) and then re-enables FBC in the page-flip finish work
>function, so that the registers are now pointing to the new framebuffer.
>Ideally, we want to only re-enable FBC after page-flipping is complete,
>as otherwise we are just wasting cycles (with an undesirable
>wait-for-vblank) and power (with needless recompression) whilst the
>page-flipping application is still running.
>
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> drivers/gpu/drm/i915/intel_display.c |    2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>index 6071d2e..7bb6b16 100644
>--- a/drivers/gpu/drm/i915/intel_display.c
>+++ b/drivers/gpu/drm/i915/intel_display.c
>@@ -6135,6 +6135,7 @@ static void intel_unpin_work_fn(struct work_struct *__work)
> 	drm_gem_object_unreference(&work->pending_flip_obj->base);
> 	drm_gem_object_unreference(&work->old_fb_obj->base);
> 
>+	intel_update_fbc(work->dev);
> 	mutex_unlock(&work->dev->struct_mutex);
> 	kfree(work);
> }
>@@ -6499,6 +6500,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
> 	if (ret)
> 		goto cleanup_pending;
> 
>+	intel_disable_fbc(dev);
> 	mutex_unlock(&dev->struct_mutex);
> 
> 	trace_i915_flip_request(intel_crtc->plane, obj);
>-- 
>1.7.6
>

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Attachments on bug 33487: 42539 | 44487 | 48741 | 48840 | 48844

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