drm/amdgpu: Only disable prefer_shadow on hawaii

We changed it for all asics due to a hibernation regression
on hawaii, but the workaround breaks suspend on a polaris12.
Just disable it for hawaii.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216119
Fixes: 3a4b1cc28fbd ("drm/amdgpu/display: disable prefer_shadow for generic fb helpers")
Reviewed-and-tested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 08906c7..5140d9c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3825,8 +3825,11 @@ static int amdgpu_dm_mode_config_init(struct amdgpu_device *adev)
 	adev_to_drm(adev)->mode_config.max_height = 16384;
 
 	adev_to_drm(adev)->mode_config.preferred_depth = 24;
-	/* disable prefer shadow for now due to hibernation issues */
-	adev_to_drm(adev)->mode_config.prefer_shadow = 0;
+	if (adev->asic_type == CHIP_HAWAII)
+		/* disable prefer shadow for now due to hibernation issues */
+		adev_to_drm(adev)->mode_config.prefer_shadow = 0;
+	else
+		adev_to_drm(adev)->mode_config.prefer_shadow = 1;
 	/* indicates support for immediate flip */
 	adev_to_drm(adev)->mode_config.async_page_flip = true;