radeon: Fix locking in power management paths

The ttm code could take vram_mutex followed by cp_mutex, while the
reclocking code would do the reverse. Hilarity could ensue.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 7cc54c8..134b195 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -61,6 +61,8 @@ static void radeon_pm_set_clocks(struct radeon_device *rdev, int static_switch)
        if (!static_switch)
                radeon_get_power_state(rdev, rdev->pm.planned_action);
 
+       mutex_lock(&rdev->ddev->struct_mutex);
+       mutex_lock(&rdev->vram_mutex);
        mutex_lock(&rdev->cp.mutex);
 
        /* wait for GPU idle */
@@ -73,8 +75,6 @@ static void radeon_pm_set_clocks(struct radeon_device *rdev, int static_switch)
        rdev->irq.gui_idle = false;
        radeon_irq_set(rdev);
 
-       mutex_lock(&rdev->vram_mutex);
-
        radeon_unmap_vram_bos(rdev);
 
        if (!static_switch) {
@@ -97,8 +97,6 @@ static void radeon_pm_set_clocks(struct radeon_device *rdev, int static_switch)
                }
        }
 
-       mutex_unlock(&rdev->vram_mutex);
-       
        /* update display watermarks based on new power state */
        radeon_update_bandwidth_info(rdev);
        if (rdev->pm.active_crtc_count)
@@ -107,6 +105,8 @@ static void radeon_pm_set_clocks(struct radeon_device *rdev, int static_switch)
        rdev->pm.planned_action = PM_ACTION_NONE;
 
        mutex_unlock(&rdev->cp.mutex);
+       mutex_unlock(&rdev->vram_mutex);
+       mutex_unlock(&rdev->ddev->struct_mutex);
 }
 
 static ssize_t radeon_get_power_state_static(struct device *dev,
@@ -134,7 +134,6 @@ static ssize_t radeon_set_power_state_static(struct device *dev,
                return count;
        }
 
-       mutex_lock(&rdev->ddev->struct_mutex);
        mutex_lock(&rdev->pm.mutex);
        if ((ps >= 0) && (ps < rdev->pm.num_power_states) &&
            (cm >= 0) && (cm < rdev->pm.power_state[ps].num_clock_modes)) {
@@ -152,7 +151,6 @@ static ssize_t radeon_set_power_state_static(struct device *dev,
        } else
                DRM_ERROR("Invalid power state: %d.%d\n\n", ps, cm);
        mutex_unlock(&rdev->pm.mutex);
-       mutex_unlock(&rdev->ddev->struct_mutex);
 
        return count;
 }
@@ -189,13 +187,11 @@ static ssize_t radeon_set_dynpm(struct device *dev,
        } else if (tmp == 1) {
                if (rdev->pm.num_power_states > 1) {
                        /* enable dynpm */
-                       mutex_lock(&rdev->ddev->struct_mutex);
                        mutex_lock(&rdev->pm.mutex);
                        rdev->pm.state = PM_STATE_PAUSED;
                        rdev->pm.planned_action = PM_ACTION_DEFAULT;
                        radeon_get_power_state(rdev, rdev->pm.planned_action);
                        mutex_unlock(&rdev->pm.mutex);
-                       mutex_unlock(&rdev->ddev->struct_mutex);
                        /* update power mode info */
                        radeon_pm_compute_clocks(rdev);
                        DRM_INFO("radeon: dynamic power management enabled\n");
@@ -318,11 +314,9 @@ void radeon_pm_fini(struct radeon_device *rdev)
                   (rdev->pm.current_clock_mode_index != 0)) {
                rdev->pm.requested_power_state_index = rdev->pm.default_power_state_index;
                rdev->pm.requested_clock_mode_index = 0;
-               mutex_lock(&rdev->ddev->struct_mutex);
                mutex_lock(&rdev->pm.mutex);
                radeon_pm_set_clocks(rdev, true);
                mutex_unlock(&rdev->pm.mutex);
-               mutex_unlock(&rdev->ddev->struct_mutex);
        }
 
        device_remove_file(rdev->dev, &dev_attr_power_state);
@@ -341,7 +335,6 @@ void radeon_pm_compute_clocks(struct radeon_device *rdev)
        if (rdev->pm.state == PM_STATE_DISABLED)
                return;
 
-       mutex_lock(&rdev->ddev->struct_mutex);
        mutex_lock(&rdev->pm.mutex);
 
        rdev->pm.active_crtcs = 0;
@@ -392,7 +385,6 @@ void radeon_pm_compute_clocks(struct radeon_device *rdev)
        }
 
        mutex_unlock(&rdev->pm.mutex);
-       mutex_unlock(&rdev->ddev->struct_mutex);
 }
 
 bool radeon_pm_debug_check_in_vbl(struct radeon_device *rdev, bool finish)
@@ -468,7 +460,6 @@ static void radeon_pm_idle_work_handler(struct work_struct *work)
                                pm.idle_work.work);
 
        resched = ttm_bo_lock_delayed_workqueue(&rdev->mman.bdev);
-       mutex_lock(&rdev->ddev->struct_mutex);
        mutex_lock(&rdev->pm.mutex);
        if (rdev->pm.state == PM_STATE_ACTIVE) {
                unsigned long irq_flags;
@@ -513,7 +504,6 @@ static void radeon_pm_idle_work_handler(struct work_struct *work)
                }
        }
        mutex_unlock(&rdev->pm.mutex);
-       mutex_unlock(&rdev->ddev->struct_mutex);
        ttm_bo_unlock_delayed_workqueue(&rdev->mman.bdev, resched);
 
        queue_delayed_work(rdev->wq, &rdev->pm.idle_work,