[PATCH 4.17 42/42] net: mvneta: fix mvneta_config_rss on armada 3700

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>

[ Upstream commit 0f5c6c30a0f8c629b92ecdaef61b315c43fde10a ]

The mvneta Ethernet driver is used on a few different Marvell SoCs.
Some SoCs have per cpu interrupts for Ethernet events, the driver uses
a per CPU napi structure for this case. Some SoCs such as armada 3700
have a single interrupt for Ethernet events, the driver uses a global
napi structure for this case.

Current mvneta_config_rss() always operates the per cpu napi structure.
Fix it by operating a global napi for "single interrupt" case, and per
cpu napi structure for remaining cases.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
Fixes: 2636ac3cc2b4 ("net: mvneta: Add network support for Armada 3700 SoC")
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/marvell/mvneta.c |   35 +++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -4020,13 +4020,18 @@ static int  mvneta_config_rss(struct mvn
 
 	on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);
 
-	/* We have to synchronise on the napi of each CPU */
-	for_each_online_cpu(cpu) {
-		struct mvneta_pcpu_port *pcpu_port =
-			per_cpu_ptr(pp->ports, cpu);
-
-		napi_synchronize(&pcpu_port->napi);
-		napi_disable(&pcpu_port->napi);
+	if (!pp->neta_armada3700) {
+		/* We have to synchronise on the napi of each CPU */
+		for_each_online_cpu(cpu) {
+			struct mvneta_pcpu_port *pcpu_port =
+				per_cpu_ptr(pp->ports, cpu);
+
+			napi_synchronize(&pcpu_port->napi);
+			napi_disable(&pcpu_port->napi);
+		}
+	} else {
+		napi_synchronize(&pp->napi);
+		napi_disable(&pp->napi);
 	}
 
 	pp->rxq_def = pp->indir[0];
@@ -4043,12 +4048,16 @@ static int  mvneta_config_rss(struct mvn
 	mvneta_percpu_elect(pp);
 	spin_unlock(&pp->lock);
 
-	/* We have to synchronise on the napi of each CPU */
-	for_each_online_cpu(cpu) {
-		struct mvneta_pcpu_port *pcpu_port =
-			per_cpu_ptr(pp->ports, cpu);
-
-		napi_enable(&pcpu_port->napi);
+	if (!pp->neta_armada3700) {
+		/* We have to synchronise on the napi of each CPU */
+		for_each_online_cpu(cpu) {
+			struct mvneta_pcpu_port *pcpu_port =
+				per_cpu_ptr(pp->ports, cpu);
+
+			napi_enable(&pcpu_port->napi);
+		}
+	} else {
+		napi_enable(&pp->napi);
 	}
 
 	netif_tx_start_all_queues(pp->dev);