[PATCH 5.5 004/176] net: macb: ensure interface is not suspended on at91rm9200

Greg Kroah-Hartman
2020-03-03T18:13:39Z

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/cadence/macb_main.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -3751,6 +3751,10 @@ static int at91ether_open(struct net_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));
@@ -3815,7 +3819,7 @@ static int at91ether_close(struct net_de
q->rx_buffers, q->rx_buffers_dma);
q->rx_buffers = NULL;

- return 0;
+ return pm_runtime_put(&lp->pdev->dev);
}

/* Transmit packet */