drm/i915: Flush the CSB pointer reset

The HW resets it CSB tail pointer on resetting the engine. Most of the
time. In case it doesn't (and for system resume) we write the expected
value anyway. For extra paranoia, flush the write before we invalidate
the cacheline.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190412110159.10495-1-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2019-04-12 12:01:59 +01:00
parent fa9d38f65d
commit 0edda1d681

View File

@ -1866,6 +1866,7 @@ static void reset_csb_pointers(struct intel_engine_execlists *execlists)
*/
execlists->csb_head = reset_value;
WRITE_ONCE(*execlists->csb_write, reset_value);
wmb(); /* Make sure this is visible to HW (paranoia?) */
invalidate_csb_entries(&execlists->csb_status[0],
&execlists->csb_status[reset_value]);