drm/radeon/kms: wait for gpu idle before changing power mode

set proper wait condition as noted by Rafał Miłecki.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 6dfeb9cf16ba..4ece89aa26f8 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -378,6 +378,16 @@ static void radeon_pm_set_clocks(struct radeon_device *rdev)
         radeon_get_power_state(rdev, rdev->pm.planned_action);
         mutex_lock(&rdev->cp.mutex);
 
+        /* wait for GPU idle */
+        rdev->pm.gui_idle = false;
+        rdev->irq.gui_idle = true;
+        radeon_irq_set(rdev);
+        wait_event_interruptible_timeout(
+                rdev->irq.idle_queue, rdev->pm.gui_idle,
+                msecs_to_jiffies(RADEON_WAIT_IDLE_TIMEOUT));
+        rdev->irq.gui_idle = false;
+        radeon_irq_set(rdev);
+
         if (rdev->pm.active_crtcs & (1 << 0)) {
                 rdev->pm.req_vblank |= (1 << 0);
                 drm_vblank_get(rdev->ddev, 0);