[PATCH] drm/radeon: Reset ASIC if suspend is not managed by platform firmware

[Kai-Heng Feng]

Suspend with s2idle or by the following steps cause screen frozen:
 # echo devices > /sys/power/pm_test
 # echo freeze > /sys/power/mem

[  289.625461] [drm:uvd_v1_0_ib_test [radeon]] *ERROR* radeon: fence wait timed out.
[  289.625494] [drm:radeon_ib_ring_tests [radeon]] *ERROR* radeon: failed testing IB on ring 5 (-110).

The issue doesn't happen on traditional S3, probably because firmware or
hardware provides extra power management.

Inspired by Daniel Drake's patch [1] on amdgpu, using a similar approach
can fix the issue.

[1] https://patchwork.freedesktop.org/patch/335839/

Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/gpu/drm/radeon/radeon_device.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 266e3cbbd09b..df823b9ad79f 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -33,6 +33,7 @@
 #include <linux/slab.h>
 #include <linux/vga_switcheroo.h>
 #include <linux/vgaarb.h>
+#include <linux/suspend.h>
 
 #include <drm/drm_cache.h>
 #include <drm/drm_crtc_helper.h>
@@ -1643,6 +1644,8 @@ int radeon_suspend_kms(struct drm_device *dev, bool suspend,
 		rdev->asic->asic_reset(rdev, true);
 		pci_restore_state(dev->pdev);
 	} else if (suspend) {
+		if (pm_suspend_no_platform())
+			rdev->asic->asic_reset(rdev, true);
 		/* Shut down the device */
 		pci_disable_device(dev->pdev);
 		pci_set_power_state(dev->pdev, PCI_D3hot);
-- 
2.17.1