If the user bypasses i915 and accesses mmio directly, that easily confuses our automatic mmio debugging (any error we then detect is likely to be as a result of the user). Since we expect userspace to open debugfs/i915_forcewake_user if i915.ko is loaded and they want mmio access, that makes the opportune time to disable our debugging for duration of the bypass.
References: https://bugs.freedesktop.org/show_bug.cgi?id=102543 Signed-off-by: Chris Wilson <[email protected]> Cc: Mika Kuoppala <[email protected]> --- drivers/gpu/drm/i915/i915_debugfs.c | 32 ++++++++++++++++++++++++++++++-- drivers/gpu/drm/i915/intel_uncore.h | 7 +++++++ 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 48572b157222..d63b3c5c2f83 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4679,7 +4679,21 @@ static int i915_forcewake_open(struct inode *inode, struct file *file) return 0; intel_runtime_pm_get(dev_priv); - intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL); + + spin_lock_irq(&dev_priv->uncore.lock); + if (!dev_priv->uncore.user_forcewake.count++) { + intel_uncore_forcewake_get__locked(dev_priv, FORCEWAKE_ALL); + + /* Save and disable mmio debugging for the user bypass */ + dev_priv->uncore.user_forcewake.saved_mmio_check = + dev_priv->uncore.unclaimed_mmio_check; + dev_priv->uncore.user_forcewake.saved_mmio_debug = + i915.mmio_debug; + + dev_priv->uncore.unclaimed_mmio_check = 0; + i915.mmio_debug = 0; + } + spin_unlock_irq(&dev_priv->uncore.lock); return 0; } @@ -4691,7 +4705,21 @@ static int i915_forcewake_release(struct inode *inode, struct file *file) if (INTEL_GEN(dev_priv) < 6) return 0; - intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL); + spin_lock_irq(&dev_priv->uncore.lock); + if (!--dev_priv->uncore.user_forcewake.count) { + if (intel_uncore_unclaimed_mmio(dev_priv)) + dev_info(dev_priv->drm.dev, + "Unclaimed mmio occurred during user acess\n"); + + dev_priv->uncore.unclaimed_mmio_check = + dev_priv->uncore.user_forcewake.saved_mmio_check; + i915.mmio_debug = + dev_priv->uncore.user_forcewake.saved_mmio_debug; + + intel_uncore_forcewake_put__locked(dev_priv, FORCEWAKE_ALL); + } + spin_unlock_irq(&dev_priv->uncore.lock); + intel_runtime_pm_put(dev_priv); return 0; diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h index 5f90278da461..1acf24c6e9ce 100644 --- a/drivers/gpu/drm/i915/intel_uncore.h +++ b/drivers/gpu/drm/i915/intel_uncore.h @@ -102,6 +102,13 @@ struct intel_uncore { i915_reg_t reg_ack; } fw_domain[FW_DOMAIN_ID_COUNT]; + struct { + unsigned int count; + + int saved_mmio_check; + int saved_mmio_debug; + } user_forcewake; + int unclaimed_mmio_check; }; -- 2.14.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
