From 9ce9d0695d15da23ffe817516ba5d0b58caf8d05 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 8 Jul 2011 12:22:40 +0100 Subject: [PATCH] drm/i915: Set persistent-mode for ILK/SNB framebuffer compression Persistent mode is intended for use with front-buffer rendering, such as X, where it is necessary to detect writes to the scanout either by the GPU or through the CPU's fence, and recompress the dirty regions on the fly. (By comparison to the back-buffer rendering, the scanout is always recompressed after a page-flip.) References: https://bugs.freedesktop.org/show_bug.cgi?id=33487 References: https://bugs.freedesktop.org/show_bug.cgi?id=31742 Signed-off-by: Ben Widawsky Signed-off-by: Chris Wilson Reviewed-by: Jesse Barnes Signed-off-by: Keith Packard --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_display.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 4a446b116e6a..96fb0fa47c40 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -579,6 +579,7 @@ #define DPFC_CTL_PLANEA (0<<30) #define DPFC_CTL_PLANEB (1<<30) #define DPFC_CTL_FENCE_EN (1<<29) +#define DPFC_CTL_PERSISTENT_MODE (1<<25) #define DPFC_SR_EN (1<<10) #define DPFC_CTL_LIMIT_1X (0<<6) #define DPFC_CTL_LIMIT_2X (1<<6) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 31c75266a456..9df96bdc002e 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1581,6 +1581,8 @@ static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval) dpfc_ctl &= DPFC_RESERVED; dpfc_ctl |= (plane | DPFC_CTL_LIMIT_1X); + /* Set persistent mode for front-buffer rendering, ala X. */ + dpfc_ctl |= DPFC_CTL_PERSISTENT_MODE; dpfc_ctl |= (DPFC_CTL_FENCE_EN | dev_priv->cfb_fence); I915_WRITE(ILK_DPFC_CHICKEN, DPFC_HT_MODIFY); -- 2.39.5