drm/i915: Fix crash while aborting hibernation

Commit cbda12d77ea590082edb6d30bd342a67ebc459e0 (drm/i915: implement
new pm ops for i915) introduced the problem that if s2disk hibernation
is aborted, the system will crash, because i915_pm_freeze() does
nothing, while it should at least reverse some operations carried out
by i915_suspend().

Fix this issue by splitting the i915 suspend into a freeze part a
suspend part, where the latter is not executed before creating a
hibernation image, and the i915 resume into a "low-level" resume part
and a thaw part, where the former is not executed after the image has
been created.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 101 insertions, 67 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index ecac882e1d5..79beffcf593 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -174,78 +174,100 @@ const static struct pci_device_id pciidlist[] = {
 MODULE_DEVICE_TABLE(pci, pciidlist);
 #endif
 
-static int i915_suspend(struct drm_device *dev, pm_message_t state)
+static int i915_drm_freeze(struct drm_device *dev)
 {
-        struct drm_i915_private *dev_priv = dev->dev_private;
-
-        if (!dev || !dev_priv) {
-                DRM_ERROR("dev: %p, dev_priv: %p\n", dev, dev_priv);
-                DRM_ERROR("DRM not initialized, aborting suspend.\n");
-                return -ENODEV;
-        }
-
-        if (state.event == PM_EVENT_PRETHAW)
-                return 0;
-
         pci_save_state(dev->pdev);
 
         /* If KMS is active, we do the leavevt stuff here */
         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
-                if (i915_gem_idle(dev))
+                int error = i915_gem_idle(dev);
+                if (error) {
                         dev_err(&dev->pdev->dev,
-                                "GEM idle failed, resume may fail\n");
+                                "GEM idle failed, resume might fail\n");
+                        return error;
+                }
                 drm_irq_uninstall(dev);
         }
 
         i915_save_state(dev);
 
+        return 0;
+}
+
+static void i915_drm_suspend(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+
         intel_opregion_free(dev, 1);
 
+        /* Modeset on resume, not lid events */
+        dev_priv->modeset_on_lid = 0;
+}
+
+static int i915_suspend(struct drm_device *dev, pm_message_t state)
+{
+        int error;
+
+        if (!dev || !dev->dev_private) {
+                DRM_ERROR("dev: %p\n", dev);
+                DRM_ERROR("DRM not initialized, aborting suspend.\n");
+                return -ENODEV;
+        }
+
+        if (state.event == PM_EVENT_PRETHAW)
+                return 0;
+
+        error = i915_drm_freeze(dev);
+        if (error)
+                return error;
+
+        i915_drm_suspend(dev);
+
         if (state.event == PM_EVENT_SUSPEND) {
                 /* Shut down the device */
                 pci_disable_device(dev->pdev);
                 pci_set_power_state(dev->pdev, PCI_D3hot);
         }
 
-        /* Modeset on resume, not lid events */
-        dev_priv->modeset_on_lid = 0;
-
         return 0;
 }
 
-static int i915_resume(struct drm_device *dev)
+static int i915_drm_thaw(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
-        int ret = 0;
-
-        if (pci_enable_device(dev->pdev))
-                return -1;
-        pci_set_master(dev->pdev);
-
-        i915_restore_state(dev);
-
-        intel_opregion_init(dev, 1);
+        int error = 0;
 
         /* KMS EnterVT equivalent */
         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
                 mutex_lock(&dev->struct_mutex);
                 dev_priv->mm.suspended = 0;
 
-                ret = i915_gem_init_ringbuffer(dev);
-                if (ret != 0)
-                        ret = -1;
+                error = i915_gem_init_ringbuffer(dev);
                 mutex_unlock(&dev->struct_mutex);
 
                 drm_irq_install(dev);
-        }
-        if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+
                 /* Resume the modeset for every activated CRTC */
                 drm_helper_resume_force_mode(dev);
         }
 
         dev_priv->modeset_on_lid = 0;
 
-        return ret;
+        return error;
+}
+
+static int i915_resume(struct drm_device *dev)
+{
+        if (pci_enable_device(dev->pdev))
+                return -EIO;
+
+        pci_set_master(dev->pdev);
+
+        i915_restore_state(dev);
+
+        intel_opregion_init(dev, 1);
+
+        return i915_drm_thaw(dev);
 }
 
 /**
@@ -386,57 +408,69 @@ i915_pci_remove(struct pci_dev *pdev)
         drm_put_dev(dev);
 }
 
-static int
-i915_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+static int i915_pm_suspend(struct device *dev)
 {
-        struct drm_device *dev = pci_get_drvdata(pdev);
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct drm_device *drm_dev = pci_get_drvdata(pdev);
+        int error;
 
-        return i915_suspend(dev, state);
-}
+        if (!drm_dev || !drm_dev->dev_private) {
+                dev_err(dev, "DRM not initialized, aborting suspend.\n");
+                return -ENODEV;
+        }
 
-static int
-i915_pci_resume(struct pci_dev *pdev)
-{
-        struct drm_device *dev = pci_get_drvdata(pdev);
+        error = i915_drm_freeze(drm_dev);
+        if (error)
+                return error;
 
-        return i915_resume(dev);
-}
+        i915_drm_suspend(drm_dev);
 
-static int
-i915_pm_suspend(struct device *dev)
-{
-        return i915_pci_suspend(to_pci_dev(dev), PMSG_SUSPEND);
-}
+        pci_disable_device(pdev);
+        pci_set_power_state(pdev, PCI_D3hot);
 
-static int
-i915_pm_resume(struct device *dev)
-{
-        return i915_pci_resume(to_pci_dev(dev));
+        return 0;
 }
 
-static int
-i915_pm_freeze(struct device *dev)
+static int i915_pm_resume(struct device *dev)
 {
-        return i915_pci_suspend(to_pci_dev(dev), PMSG_FREEZE);
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct drm_device *drm_dev = pci_get_drvdata(pdev);
+
+        return i915_resume(drm_dev);
 }
 
-static int
-i915_pm_thaw(struct device *dev)
+static int i915_pm_freeze(struct device *dev)
 {
-        /* thaw during hibernate, do nothing! */
-        return 0;
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct drm_device *drm_dev = pci_get_drvdata(pdev);
+
+        if (!drm_dev || !drm_dev->dev_private) {
+                dev_err(dev, "DRM not initialized, aborting suspend.\n");
+                return -ENODEV;
+        }
+
+        return i915_drm_freeze(drm_dev);
 }
 
-static int
-i915_pm_poweroff(struct device *dev)
+static int i915_pm_thaw(struct device *dev)
 {
-        return i915_pci_suspend(to_pci_dev(dev), PMSG_HIBERNATE);
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct drm_device *drm_dev = pci_get_drvdata(pdev);
+
+        return i915_drm_thaw(drm_dev);
 }
 
-static int
-i915_pm_restore(struct device *dev)
+static int i915_pm_poweroff(struct device *dev)
 {
-        return i915_pci_resume(to_pci_dev(dev));
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct drm_device *drm_dev = pci_get_drvdata(pdev);
+        int error;
+
+        error = i915_drm_freeze(drm_dev);
+        if (!error)
+                i915_drm_suspend(drm_dev);
+
+        return error;
 }
 
 const struct dev_pm_ops i915_pm_ops = {
@@ -445,7 +479,7 @@ const struct dev_pm_ops i915_pm_ops = {
      .freeze = i915_pm_freeze,
      .thaw = i915_pm_thaw,
      .poweroff = i915_pm_poweroff,
-     .restore = i915_pm_restore,
+     .restore = i915_pm_resume,
 };
 
 static struct vm_operations_struct i915_gem_vm_ops = {