From d6a8b72edc92471283925ceb4ba12799b67c3ff8 Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi Date: Wed, 5 Nov 2014 16:56:36 -0800 Subject: [PATCH 1/3] drm/i915: Disable caches for Global GTT. Global GTT doesn't have pat_sel[2:0] so it always point to pat_sel = 000; So the only way to avoid screen corruptions is setting PAT 0 to Uncached. MOCS can still be used though. But if userspace is trusting PTE for cache selection the safest thing to do is to let caches disabled. BSpec: "For GGTT, there is NO pat_sel[2:0] from the entry, so RTL will always use the value corresponding to pat_sel = 000" - System agent ggtt writes (i.e. cpu gtt mmaps) already work before this patch, i.e. the same uncached + snooping access like on gen6/7 seems to be in effect. - So this just fixes blitter/render access. Again it looks like it's not just uncached access, but uncached + snooping. So we can still hold onto all our assumptions wrt cpu clflushing on LLC machines. v2: Cleaner patch as suggested by Chris. v3: Add Daniel's comment Reference: https://bugs.freedesktop.org/show_bug.cgi?id=85576 Cc: Chris Wilson Cc: James Ausmus Cc: Daniel Vetter Cc: Jani Nikula Cc: Stable@vger.kernel.org Tested-by: James Ausmus Reviewed-by: James Ausmus Signed-off-by: Rodrigo Vivi Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_gem_gtt.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index b672b843fd5e..728938f02341 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1902,6 +1902,22 @@ static void bdw_setup_private_ppat(struct drm_i915_private *dev_priv) GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) | GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3)); + if (!USES_PPGTT(dev_priv->dev)) + /* Spec: "For GGTT, there is NO pat_sel[2:0] from the entry, + * so RTL will always use the value corresponding to + * pat_sel = 000". + * So let's disable cache for GGTT to avoid screen corruptions. + * MOCS still can be used though. + * - System agent ggtt writes (i.e. cpu gtt mmaps) already work + * before this patch, i.e. the same uncached + snooping access + * like on gen6/7 seems to be in effect. + * - So this just fixes blitter/render access. Again it looks + * like it's not just uncached access, but uncached + snooping. + * So we can still hold onto all our assumptions wrt cpu + * clflushing on LLC machines. + */ + pat = GEN8_PPAT(0, GEN8_PPAT_UC); + /* XXX: spec defines this as 2 distinct registers. It's unclear if a 64b * write would work. */ I915_WRITE(GEN8_PRIVATE_PAT, pat); From a024d2e6f11836493d9e1751fca7b3c50fbfd215 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Wed, 10 Sep 2014 18:16:54 +0300 Subject: [PATCH 2/3] drm/i915: vlv: fix gunit HW state corruption during S4 suspend MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During S4 freeze we don't call intel_suspend_complete(), which would save the gunit HW state, but during S4 thaw/restore events we call intel_resume_prepare() which restores it, thus ending up in a corrupted HW state. Fix this by calling intel_suspend_complete() from the corresponding freeze_late event handler. The issue was introduced in commit 016970beb05da6285c2f3ed2bee1c676cb75972e Author: Sagar Kamble Date: Wed Aug 13 23:07:06 2014 +0530 CC: Sagar Kamble Signed-off-by: Imre Deak Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_drv.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 055d5e7fbf12..2318b4c7a8f8 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -986,6 +986,15 @@ static int i915_pm_freeze(struct device *dev) return i915_drm_freeze(drm_dev); } +static int i915_pm_freeze_late(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct drm_device *drm_dev = pci_get_drvdata(pdev); + struct drm_i915_private *dev_priv = drm_dev->dev_private; + + return intel_suspend_complete(dev_priv); +} + static int i915_pm_thaw_early(struct device *dev) { struct pci_dev *pdev = to_pci_dev(dev); @@ -1570,6 +1579,7 @@ static const struct dev_pm_ops i915_pm_ops = { .resume_early = i915_pm_resume_early, .resume = i915_pm_resume, .freeze = i915_pm_freeze, + .freeze_late = i915_pm_freeze_late, .thaw_early = i915_pm_thaw_early, .thaw = i915_pm_thaw, .poweroff = i915_pm_poweroff, From e1c412e75754ab7b7002f3e18a2652d999c40d4b Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Wed, 5 Nov 2014 14:46:31 +0200 Subject: [PATCH 3/3] drm/i915: safeguard against too high minimum brightness Never trust (your interpretation of) the VBT. Regression from commit 6dda730e55f412a6dfb181cae6784822ba463847 Author: Jani Nikula Date: Tue Jun 24 18:27:40 2014 +0300 drm/i915: respect the VBT minimum backlight brightness causing div by zero if VBT minimum brightness equals maximum brightness. Despite my attempts I've failed in my detective work to figure out what the root cause is. This is not the real fix, but we have to do something. Reported-by: Mike Auty Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=86551 Cc: stable@vger.kernel.org (v3.17+) Reviewed-by: Daniel Vetter Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_panel.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 0e018cb49147..41b3be217493 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -1098,12 +1098,25 @@ static u32 get_backlight_min_vbt(struct intel_connector *connector) struct drm_device *dev = connector->base.dev; struct drm_i915_private *dev_priv = dev->dev_private; struct intel_panel *panel = &connector->panel; + int min; WARN_ON(panel->backlight.max == 0); + /* + * XXX: If the vbt value is 255, it makes min equal to max, which leads + * to problems. There are such machines out there. Either our + * interpretation is wrong or the vbt has bogus data. Or both. Safeguard + * against this by letting the minimum be at most (arbitrarily chosen) + * 25% of the max. + */ + min = clamp_t(int, dev_priv->vbt.backlight.min_brightness, 0, 64); + if (min != dev_priv->vbt.backlight.min_brightness) { + DRM_DEBUG_KMS("clamping VBT min backlight %d/255 to %d/255\n", + dev_priv->vbt.backlight.min_brightness, min); + } + /* vbt value is a coefficient in range [0..255] */ - return scale(dev_priv->vbt.backlight.min_brightness, 0, 255, - 0, panel->backlight.max); + return scale(min, 0, 255, 0, panel->backlight.max); } static int bdw_setup_backlight(struct intel_connector *connector)