[Intel-gfx] [PATCH] drm/i915: On reset/suspend disable hpd pins & cancel pending delayed work

[Egbert Eich]

This makes sure no hpd interrupt or reenable worker fires when
resetting or suspending.
We already call intel_hpd_init() in most cases on resume and
after reset to undo this.

Signed-off-by: Egbert Eich <eich at suse.de>
---
 drivers/gpu/drm/i915/i915_drv.c      |  3 +++
 drivers/gpu/drm/i915/i915_drv.h      |  1 +
 drivers/gpu/drm/i915/intel_display.c |  5 +++--
 drivers/gpu/drm/i915/intel_hotplug.c | 28 ++++++++++++++++++++++++++++
 4 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index e2bf9e2..cb8d75f 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -620,6 +620,7 @@ static int i915_drm_suspend(struct drm_device *dev)
 
 	intel_dp_mst_suspend(dev);
 
+	intel_hpd_uninit(dev_priv);
 	intel_runtime_pm_disable_interrupts(dev_priv);
 	intel_hpd_cancel_work(dev_priv);
 
@@ -1477,12 +1478,14 @@ static int intel_runtime_suspend(struct device *device)
 	mutex_unlock(&dev->struct_mutex);
 
 	intel_suspend_gt_powersave(dev);
+	intel_hpd_uninit(dev_priv);
 	intel_runtime_pm_disable_interrupts(dev_priv);
 
 	ret = intel_suspend_complete(dev_priv);
 	if (ret) {
 		DRM_ERROR("Runtime suspend failed, disabling it (%d)\n", ret);
 		intel_runtime_pm_enable_interrupts(dev_priv);
+		intel_hpd_init(dev_priv);
 
 		return ret;
 	}
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a6b7576..3c06629 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2688,6 +2688,7 @@ void i915_firmware_load_error_print(const char *fw_path, int err);
 /* intel_hotplug.c */
 void intel_hpd_irq_handler(struct drm_device *dev, u32 pin_mask, u32 long_mask);
 void intel_hpd_init(struct drm_i915_private *dev_priv);
+void intel_hpd_uninit(struct drm_i915_private *dev_priv);
 void intel_hpd_init_work(struct drm_i915_private *dev_priv);
 void intel_hpd_cancel_work(struct drm_i915_private *dev_priv);
 bool intel_hpd_pin_to_port(enum hpd_pin pin, enum port *port);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index fc00867..fadd4f2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3207,16 +3207,17 @@ void intel_finish_reset(struct drm_device *dev)
 	 * The display has been reset as well,
 	 * so need a full re-initialization.
 	 */
+	intel_hpd_uninit(dev_priv);
 	intel_runtime_pm_disable_interrupts(dev_priv);
 	intel_runtime_pm_enable_interrupts(dev_priv);
 
 	intel_modeset_init_hw(dev);
-
+#if 0
 	spin_lock_irq(&dev_priv->irq_lock);
 	if (dev_priv->display.hpd_irq_setup)
 		dev_priv->display.hpd_irq_setup(dev);
 	spin_unlock_irq(&dev_priv->irq_lock);
-
+#endif
 	intel_display_resume(dev);
 
 	intel_hpd_init(dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
index b177857..4f2a179 100644
--- a/drivers/gpu/drm/i915/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/intel_hotplug.c
@@ -484,6 +484,34 @@ void intel_hpd_init(struct drm_i915_private *dev_priv)
 	spin_unlock_irq(&dev_priv->irq_lock);
 }
 
+/**
+ * intel_hpd_uninit - disable and deinitialize hpd support
+ * @dev_priv: i915 device instance
+ *
+ * This function disables any pending delayed work for HPD and
+ * disables all hpd pins. Calling this during suspend/reset
+ * avoids conflicts with the reenable worker of interrupt handler
+ * firing.
+ * At resume we call intel_hpd_init() to reenable things.
+ */
+void intel_hpd_uninit(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *dev = dev_priv->dev;
+	int i;
+
+	cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);
+
+	spin_lock_irq(&dev_priv->irq_lock);
+
+	for_each_hpd_pin(i) {
+		dev_priv->hotplug.stats[i].state = HPD_DISABLED;
+	}
+	if (dev_priv->display.hpd_irq_setup)
+		dev_priv->display.hpd_irq_setup(dev);
+
+	spin_unlock_irq(&dev_priv->irq_lock);
+}
+
 void intel_hpd_init_work(struct drm_i915_private *dev_priv)
 {
 	INIT_WORK(&dev_priv->hotplug.hotplug_work, i915_hotplug_work_func);
-- 
1.8.4.5