drm/xe: Enlarge the invalidation timeout from 150 to 500

There are error messages like below that are occurring during stress
testing: "[   31.004009] xe 0000:03:00.0: [drm] ERROR GT0: Global
invalidation timeout". Previously it was hitting this 3 out of 1000
executions of warm reboot.  After raising it to 500, 1000 warm reboot
executions passed and it didn't fail.

Due to the way xe_mmio_wait32() is implemented, the timeout is able to
expire early when the register matches the expected value due to the
wait increments starting small. So, the larger timeout value should have
no effect during normal use cases.

v2 (Jonathan):
  - rework the commit message
v3 (Lucas):
  - add conclusive message for the fail rate and test case
v4:
  - add suggested-by

Suggested-by: Jia Yao <[email protected]>
Signed-off-by: Shuicheng Lin <[email protected]>
Cc: Lucas De Marchi <[email protected]>
Cc: Matthew Auld <[email protected]>
Cc: Nirmoy Das <[email protected]>
Reviewed-by: Jonathan Cavitt <[email protected]>
Tested-by: Zongyao Bai <[email protected]>
Reviewed-by: Nirmoy Das <[email protected]>
Signed-off-by: Matthew Auld <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: ShuichengLin

drivers/gpu/drm/xe/xe_device.c

@@ -925,7 +925,7 @@ void xe_device_l2_flush(struct xe_device *xe)
 	spin_lock(&gt->global_invl_lock);
 	xe_mmio_write32(&gt->mmio, XE2_GLOBAL_INVAL, 0x1);
 
-	if (xe_mmio_wait32(&gt->mmio, XE2_GLOBAL_INVAL, 0x1, 0x0, 150, NULL, true))
+	if (xe_mmio_wait32(&gt->mmio, XE2_GLOBAL_INVAL, 0x1, 0x0, 500, NULL, true))
 		xe_gt_err_once(gt, "Global invalidation timeout\n");
 	spin_unlock(&gt->global_invl_lock);