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| author | Paulo Zanoni <paulo.r.zanoni@intel.com> | 2015-06-30 10:53:05 -0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-07-03 07:39:00 +0200 |
| commit | ce65e47b78789b4f78be1fd7e4c884df74a9f075 (patch) | |
| tree | 8ea1670d2220639f55c8f5bfe5c1764c6e5abf54 | |
| parent | ca1543be2c4233fbc266bf66f4320806e61e05dd (diff) | |
| download | lwn-ce65e47b78789b4f78be1fd7e4c884df74a9f075.tar.gz lwn-ce65e47b78789b4f78be1fd7e4c884df74a9f075.zip | |
drm/i915: don't increment the FBC threshold at fbc_enable
We first set the threshold value when we're allocating the CFB, and
then later at {ilk,gen7}_fbc_enable() we increment it in case we're
using 16bpp. While that is correct, it is dangerous: if we rework the
code a little bit in a way that allows us to call intel_fbc_enable()
without necessarily calling i915_gem_stolen_setup_compression() first,
we might end up incrementing threshold more than once. To prevent
that, increment a temporary variable instead.
v2: Rebase.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
| -rw-r--r-- | drivers/gpu/drm/i915/intel_fbc.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c index 50ed3332def1..9e55b9badb4b 100644 --- a/drivers/gpu/drm/i915/intel_fbc.c +++ b/drivers/gpu/drm/i915/intel_fbc.c @@ -188,14 +188,15 @@ static void ilk_fbc_enable(struct drm_crtc *crtc) struct drm_i915_gem_object *obj = intel_fb_obj(fb); struct intel_crtc *intel_crtc = to_intel_crtc(crtc); u32 dpfc_ctl; + int threshold = dev_priv->fbc.threshold; dev_priv->fbc.enabled = true; dpfc_ctl = DPFC_CTL_PLANE(intel_crtc->plane); if (drm_format_plane_cpp(fb->pixel_format, 0) == 2) - dev_priv->fbc.threshold++; + threshold++; - switch (dev_priv->fbc.threshold) { + switch (threshold) { case 4: case 3: dpfc_ctl |= DPFC_CTL_LIMIT_4X; @@ -259,6 +260,7 @@ static void gen7_fbc_enable(struct drm_crtc *crtc) struct drm_i915_gem_object *obj = intel_fb_obj(fb); struct intel_crtc *intel_crtc = to_intel_crtc(crtc); u32 dpfc_ctl; + int threshold = dev_priv->fbc.threshold; dev_priv->fbc.enabled = true; @@ -267,9 +269,9 @@ static void gen7_fbc_enable(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++; + threshold++; - switch (dev_priv->fbc.threshold) { + switch (threshold) { case 4: case 3: dpfc_ctl |= DPFC_CTL_LIMIT_4X; |