[PATCH AUTOSEL 5.4 19/58] net: macb: ensure interface is not suspended on at91rm9200

[Sasha Levin <sashal@kernel.org>]

From: Alexandre Belloni <alexandre.belloni@bootlin.com>

[ Upstream commit e6a41c23df0d5da01540d2abef41591589c0b4be ]

Because of autosuspend, at91ether_start is called with clocks disabled.
Ensure that pm_runtime doesn't suspend the interface as soon as it is
opened as there is no pm_runtime support is the other relevant parts of the
platform support for at91rm9200.

Fixes: d54f89af6cc4 ("net: macb: Add pm runtime support")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/cadence/macb_main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 95a94507cec12..234c13ebbc41b 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -3690,6 +3690,10 @@ static int at91ether_open(struct net_device *dev)
 	u32 ctl;
 	int ret;
 
+	ret = pm_runtime_get_sync(&lp->pdev->dev);
+	if (ret < 0)
+		return ret;
+
 	/* Clear internal statistics */
 	ctl = macb_readl(lp, NCR);
 	macb_writel(lp, NCR, ctl | MACB_BIT(CLRSTAT));
@@ -3750,7 +3754,7 @@ static int at91ether_close(struct net_device *dev)
 			  q->rx_buffers, q->rx_buffers_dma);
 	q->rx_buffers = NULL;
 
-	return 0;
+	return pm_runtime_put(&lp->pdev->dev);
 }
 
 /* Transmit packet */
-- 
2.20.1