From 55ec45c2ced1a4b1e7cd2e7e306101f328958760 Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Tue, 15 Dec 2015 16:25:08 +0200 Subject: [PATCH] drm/i915: Detect and clear unclaimed access on resume If something, the usual suspect being bios, access hw behind our back, don't let it slide into situation where normal register access will detect this and spit out a warn on into dmesg. On some bdw bioses this happens during igt/bat run always and as there is not much we can do about it, its better just to detect and flush this explicitly on resume and only print a debug message. v2: use DRM_DEBUG_DRIVER (Chris) v3: s/access/mmio, s/prior/prior to, s/dev/dev_priv Testcase: igt/pm_rpm/basic-rte Cc: Chris Wilson Cc: Paulo Zanoni Cc: Daniel Vetter Reviewed-by: Chris Wilson [Mika: fixed merge conflict] Signed-off-by: Mika Kuoppala Link: http://patchwork.freedesktop.org/patch/msgid/1450189512-30360-3-git-send-email-mika.kuoppala@intel.com --- drivers/gpu/drm/i915/i915_drv.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 3ac616d7363b..288fec7691dc 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1501,6 +1501,10 @@ static int intel_runtime_suspend(struct device *device) enable_rpm_wakeref_asserts(dev_priv); WARN_ON_ONCE(atomic_read(&dev_priv->pm.wakeref_count)); + + if (intel_uncore_unclaimed_mmio(dev_priv)) + DRM_ERROR("Unclaimed access detected prior to suspending\n"); + dev_priv->pm.suspended = true; /* @@ -1549,6 +1553,8 @@ static int intel_runtime_resume(struct device *device) intel_opregion_notify_adapter(dev, PCI_D0); dev_priv->pm.suspended = false; + if (intel_uncore_unclaimed_mmio(dev_priv)) + DRM_DEBUG_DRIVER("Unclaimed access during suspend, bios?\n"); intel_guc_resume(dev); -- 2.20.1