qcacmn: per_engine_service yield based on timing

Yield based on timing instead of relying purely on packet count

Change-Id: Ie464f9344f39cba7cb1f95047ce8a160b050e503
CRs-Fixed: 1017059

hif/src/ce/ce_internal.h

@@ -136,6 +136,7 @@ struct CE_state {
 	bool force_break;	/* Flag to indicate whether to
 				 * break out the DPC context */
 
+	qdf_time_t ce_service_yield_time;
 	unsigned int receive_count;	/* count Num Of Receive Buffers
 					 * handled for one interrupt
 					 * DPC routine */
@@ -388,6 +389,9 @@ struct ce_sendlist_s {
 	} item[CE_SENDLIST_ITEMS_MAX];
 };
 
+bool hif_ce_service_should_yield(struct hif_softc *scn, struct CE_state
+				 *ce_state);
+
 #ifdef WLAN_FEATURE_FASTPATH
 void ce_h2t_tx_ce_cleanup(struct CE_handle *ce_hdl);
 void ce_t2h_msg_ce_cleanup(struct CE_handle *ce_hdl);

hif/src/ce/ce_main.c

@@ -1352,7 +1352,6 @@ hif_pci_ce_recv_data(struct CE_handle *copyeng, void *ce_context,
 #endif
 	struct hif_msg_callbacks *msg_callbacks =
 		&hif_state->msg_callbacks_current;
-	uint32_t count;
 
 	do {
 #ifdef HIF_PCI
@@ -1373,8 +1372,7 @@ hif_pci_ce_recv_data(struct CE_handle *copyeng, void *ce_context,
 		/* Set up force_break flag if num of receices reaches
 		 * MAX_NUM_OF_RECEIVES */
 		ce_state->receive_count++;
-		count = ce_state->receive_count;
-		if (qdf_unlikely(hif_max_num_receives_reached(scn, count))) {
+		if (qdf_unlikely(hif_ce_service_should_yield(scn, ce_state))) {
 			ce_state->force_break = 1;
 			break;
 		}

hif/src/ce/ce_service.c

@@ -189,6 +189,22 @@ inline void ce_init_ce_desc_event_log(int ce_id, int size)
 }
 #endif
 
+/**
+ * hif_ce_service_should_yield() - return true if the service is hogging the cpu
+ * @scn: hif context
+ * @ce_state: context of the copy engine being serviced
+ *
+ * Return: true if the service should yield
+ */
+bool hif_ce_service_should_yield(struct hif_softc *scn,
+				 struct CE_state *ce_state)
+{
+	bool yield = qdf_system_time_after_eq(qdf_system_ticks(),
+					     ce_state->ce_service_yield_time) ||
+		     hif_max_num_receives_reached(scn, ce_state->receive_count);
+	return yield;
+}
+
 /*
  * Support for Copy Engine hardware, which is mainly used for
  * communication between Host and Target over a PCIe interconnect.
@@ -1738,6 +1754,7 @@ static void ce_per_engine_service_fast(struct hif_softc *scn, int ce_id)
 }
 #endif /* WLAN_FEATURE_FASTPATH */
 
+#define CE_PER_ENGINE_SERVICE_MAX_TIME_JIFFIES 2
 /*
  * Guts of interrupt handler for per-engine interrupts on a particular CE.
  *
@@ -1746,7 +1763,6 @@ static void ce_per_engine_service_fast(struct hif_softc *scn, int ce_id)
  *
  * Returns: number of messages processed
  */
-
 int ce_per_engine_service(struct hif_softc *scn, unsigned int CE_id)
 {
 	struct CE_state *CE_state = scn->ce_id_to_state[CE_id];
@@ -1790,6 +1806,8 @@ int ce_per_engine_service(struct hif_softc *scn, unsigned int CE_id)
 	/* NAPI: scn variables- thread/multi-processing safety? */
 	CE_state->receive_count = 0;
 	CE_state->force_break = 0;
+	CE_state->ce_service_yield_time = qdf_system_ticks() +
+		CE_PER_ENGINE_SERVICE_MAX_TIME_JIFFIES;
 more_completions:
 	if (CE_state->recv_cb) {