drm/xe/guc: READ/WRITE_ONCE g2h_fence->done

Use READ_ONCE and WRITE_ONCE when operating on g2h_fence->done
to prevent the compiler from ignoring important modifications
to its value.

Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20251222201957.63245-5-jonathan.cavitt@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Jonathan Cavitt
2025-12-22 20:19:59 +00:00
committed by Rodrigo Vivi
parent c3a613a039
commit b5179dbd1c

View File

@@ -206,7 +206,9 @@ static void g2h_fence_cancel(struct g2h_fence *g2h_fence)
{
g2h_fence->cancel = true;
g2h_fence->fail = true;
g2h_fence->done = true;
/* WRITE_ONCE pairs with READ_ONCEs in guc_ct_send_recv. */
WRITE_ONCE(g2h_fence->done, true);
}
static bool g2h_fence_needs_alloc(struct g2h_fence *g2h_fence)
@@ -1294,10 +1296,13 @@ retry_same_fence:
return ret;
}
ret = wait_event_timeout(ct->g2h_fence_wq, g2h_fence.done, HZ);
/* READ_ONCEs pairs with WRITE_ONCEs in parse_g2h_response
* and g2h_fence_cancel.
*/
ret = wait_event_timeout(ct->g2h_fence_wq, READ_ONCE(g2h_fence.done), HZ);
if (!ret) {
LNL_FLUSH_WORK(&ct->g2h_worker);
if (g2h_fence.done) {
if (READ_ONCE(g2h_fence.done)) {
xe_gt_warn(gt, "G2H fence %u, action %04x, done\n",
g2h_fence.seqno, action[0]);
ret = 1;
@@ -1498,7 +1503,8 @@ static int parse_g2h_response(struct xe_guc_ct *ct, u32 *msg, u32 len)
g2h_release_space(ct, GUC_CTB_HXG_MSG_MAX_LEN);
g2h_fence->done = true;
/* WRITE_ONCE pairs with READ_ONCEs in guc_ct_send_recv. */
WRITE_ONCE(g2h_fence->done, true);
smp_mb();
wake_up_all(&ct->g2h_fence_wq);