drm/amd: Forbid suspending into non-default suspend states

On systems that default to 'deep' some userspace software likes
to try to suspend in 'deep' first.  If there is a failure for any
reason (such as -ENOMEM) the failure is ignored and then it will
try to use 's2idle' as a fallback. This fails, but more importantly
it leads to graphical problems.

Forbid this behavior and only allow suspending in the last state
supported by the system.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4093
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20250408180957.4027643-1-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 2aabd44)

Author: superm1

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -1123,6 +1123,7 @@ struct amdgpu_device {
 	bool				in_s3;
 	bool				in_s4;
 	bool				in_s0ix;
+	suspend_state_t			last_suspend_state;
 
 	enum pp_mp1_state               mp1_state;
 	struct amdgpu_doorbell_index doorbell_index;

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -2548,8 +2548,20 @@ static int amdgpu_pmops_suspend(struct device *dev)
 		adev->in_s0ix = true;
 	else if (amdgpu_acpi_is_s3_active(adev))
 		adev->in_s3 = true;
-	if (!adev->in_s0ix && !adev->in_s3)
+	if (!adev->in_s0ix && !adev->in_s3) {
+		/* don't allow going deep first time followed by s2idle the next time */
+		if (adev->last_suspend_state != PM_SUSPEND_ON &&
+		    adev->last_suspend_state != pm_suspend_target_state) {
+			drm_err_once(drm_dev, "Unsupported suspend state %d\n",
+				     pm_suspend_target_state);
+			return -EINVAL;
+		}
 		return 0;
+	}
+
+	/* cache the state last used for suspend */
+	adev->last_suspend_state = pm_suspend_target_state;
+
 	return amdgpu_device_suspend(drm_dev, true);
 }