From: Antonino Maniscalco <antonino.maniscalco@xxxxxxxxxxxxx>
If the kernel couldn't allocate memory because we reached the maximum
number of chunks but no render passes are in flight
(panthor_heap_grow() returning -ENOMEM), we should defer the OOM
handling to the FW by returning a NULL chunk. The FW will then call
the tiler OOM exception handler, which is supposed to implement
incremental rendering (execute an intermediate fragment job to flush
the pending primitives, release the tiler memory that was used to
store those primitives, and start over from where it stopped).
Fixes: de8548813824 ("drm/panthor: Add the scheduler logical block")
Signed-off-by: Antonino Maniscalco <antonino.maniscalco@xxxxxxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
---
drivers/gpu/drm/panthor/panthor_sched.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index b3a51a6de523..6de8c0c702cb 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -1354,7 +1354,13 @@ static int group_process_tiler_oom(struct panthor_group *group, u32 cs_id)
pending_frag_count, &new_chunk_va);
}
- if (ret && ret != -EBUSY) {
+ /* If the kernel couldn't allocate memory because we reached the maximum
+ * number of chunks (EBUSY if we have render passes in flight, ENOMEM
+ * otherwise), we want to let the FW try to reclaim memory by waiting
+ * for fragment jobs to land or by executing the tiler OOM exception
+ * handler, which is supposed to implement incremental rendering.
+ */
+ if (ret && ret != -EBUSY && ret != -ENOMEM) {
drm_warn(&ptdev->base, "Failed to extend the tiler heap\n");
group->fatal_queues |= BIT(cs_id);
sched_queue_delayed_work(sched, tick, 0);
--
2.44.0
