qcacmn: Perform napi state comparison before releasing napi lock
Release napi spinlock only after performing napi state
comparison to avoid any race condition.
Change-Id: Icd7b713e474a818dfc6d0fa402496bbe06a3af66
CRs-Fixed: 2078294
diff --git a/hif/src/hif_napi.c b/hif/src/hif_napi.c
index e2a4236..8528b2d 100644
--- a/hif/src/hif_napi.c
+++ b/hif/src/hif_napi.c
@@ -410,6 +410,7 @@
int rc = 0;
uint32_t prev_state;
int i;
+ bool state_changed;
struct napi_struct *napi;
struct hif_softc *hif = HIF_GET_SOFTC(hif_ctx);
struct qca_napi_data *napid = &(hif->napi_data);
@@ -559,9 +560,18 @@
break;
} /* switch blacklist_pending */
+ /* we want to perform the comparison in lock:
+ * there is a possiblity of hif_napi_event get called
+ * from two different contexts (driver unload and cpu hotplug
+ * notification) and napid->state get changed
+ * in driver unload context and can lead to race condition
+ * in cpu hotplug context. Therefore, perform the napid->state
+ * comparison before releasing lock.
+ */
+ state_changed = (prev_state != napid->state);
qdf_spin_unlock_bh(&(napid->lock));
- if (prev_state != napid->state) {
+ if (state_changed) {
if (napid->state == ENABLE_NAPI_MASK) {
rc = 1;
for (i = 0; i < CE_COUNT_MAX; i++) {