drm/amdgpu: add a delay after ATPX dGPU power off

ATPX dGPU power control requires a 200ms delay between
power off and on.  This should fix dGPU failures on
resume from power off.

Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c
index 1be2ce4..c5d280c 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c
@@ -10,6 +10,7 @@
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/pci.h>
+#include <linux/delay.h>
 
 #include "amd_acpi.h"
 
@@ -271,6 +272,10 @@ static int amdgpu_atpx_set_discrete_state(struct amdgpu_atpx *atpx, u8 state)
                if (!info)
                        return -EIO;
                kfree(info);
+
+               /* 200ms delay is required after off */
+               if (state == 0)
+                       msleep(200);
        }
        return 0;
 }