diff options
| author | Jonathan Cavitt <jonathan.cavitt@intel.com> | 2025-12-22 20:19:59 +0000 |
|---|---|---|
| committer | Thomas Hellström <thomas.hellstrom@linux.intel.com> | 2025-12-29 10:49:23 +0100 |
| commit | bed2a6bd20681aacfb063015c1edfab6f58a333e (patch) | |
| tree | 7dfe3571da417f33e57a2a5b9b47401906c67d3a /drivers/gpu | |
| parent | 754c23238438600e9236719f7e67aff2c4d02093 (diff) | |
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: dd08ebf6c352 ("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>
(cherry picked from commit b5179dbd1c14743ae80f0aaa28eaaf35c361608f)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/xe/xe_guc_ct.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c index 4ac434ad216f..a5019d1e741b 100644 --- a/drivers/gpu/drm/xe/xe_guc_ct.c +++ b/drivers/gpu/drm/xe/xe_guc_ct.c @@ -104,7 +104,9 @@ 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) @@ -1203,10 +1205,13 @@ 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; @@ -1454,7 +1459,8 @@ 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); |