On Mon, 9 Sep 2019 from Gerd Hoffmann kraxel@redhat.com

Hmm, I think the patch is wrong.

Hmm...it should have added change only in the error path, leaving locks for drivers to release if job is done with no error returned.

As far I know it is the qxl drivers's job to call ttm_eu_backoff_reservation().

Like other drivers, qxl is currently doing the right.

Doing that automatically in ttm will most likely break other ttm users.

You are right. They are responsible for doing backoff if error happens while validating buffers afterwards.

--- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c @@ -111,8 +111,10 @@ int ttm_eu_reserve_buffers(struct ww_acq

list_for_each_entry(entry, list, head) { struct ttm_buffer_object *bo = entry->bo; + bool lockon;

ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket); + lockon = !ret; if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { reservation_object_unlock(bo->resv);

@@ -151,6 +153,7 @@ int ttm_eu_reserve_buffers(struct ww_acq ret = 0; } } + lockon = !ret;

if (!ret && entry->num_shared) ret = reservation_object_reserve_shared(bo->resv, @@ -163,6 +166,8 @@ int ttm_eu_reserve_buffers(struct ww_acq ww_acquire_done(ticket); ww_acquire_fini(ticket); } + if (lockon) + ttm_eu_backoff_reservation_reverse(list, entry); return ret; }

--