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 <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <przanoni@gmail.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[Mika: fixed merge conflict]
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450189512-30360-3-git-send-email-mika.kuoppala@intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 3ac616d..288fec7 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1501,6 +1501,10 @@
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 @@
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);