drm/radeon: rework and fix reset detection v2

Stop fiddling with jiffies, always wait for RADEON_FENCE_JIFFIES_TIMEOUT.
Consolidate the two wait sequence implementations into just one function.
Activate all waiters and remember if the reset was already done instead of
trying to reset from only one thread.

v2: clear reset flag earlier to avoid timeout in IB test
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon.h

@@ -328,7 +328,6 @@ struct radeon_fence_driver {
 	/* sync_seq is protected by ring emission lock */
 	uint64_t			sync_seq[RADEON_NUM_RINGS];
 	atomic64_t			last_seq;
-	unsigned long			last_activity;
 	bool				initialized;
 };
 
@@ -2171,6 +2170,7 @@ struct radeon_device {
 	bool				need_dma32;
 	bool				accel_working;
 	bool				fastfb_working; /* IGP feature*/
+	bool				needs_reset;
 	struct radeon_surface_reg surface_regs[RADEON_GEM_MAX_SURFACES];
 	const struct firmware *me_fw;	/* all family ME firmware */
 	const struct firmware *pfp_fw;	/* r6/700 PFP firmware */

drivers/gpu/drm/radeon/radeon_device.c

@@ -1574,6 +1574,14 @@ int radeon_gpu_reset(struct radeon_device *rdev)
 	int resched;
 
 	down_write(&rdev->exclusive_lock);
+
+	if (!rdev->needs_reset) {
+		up_write(&rdev->exclusive_lock);
+		return 0;
+	}
+
+	rdev->needs_reset = false;
+
 	radeon_save_bios_scratch_regs(rdev);
 	/* block TTM */
 	resched = ttm_bo_lock_delayed_workqueue(&rdev->mman.bdev);