[PATCH] net: smsc911x: Make Runtime PM handling more fine-grained
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: 2021-01-18 15:18:56
Currently the smsc911x driver has mininal power management: during driver probe, the device is powered up, and during driver remove, it is powered down. Improve power management by making it more fine-grained: 1. Power the device down when driver probe is finished, 2. Power the device (down) when it is opened (closed), 3. Make sure the device is powered during PHY access. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Tested on r8a73a4/ape6evm, where the LAN9220 is connected to a power-managed bus, and any attempt to access a device register while the device is suspended will trigger an asynchronous external abort. --- drivers/net/ethernet/smsc/smsc911x.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
index 823d9a7184fe6aa1..606c79de93a68146 100644
--- a/drivers/net/ethernet/smsc/smsc911x.c
+++ b/drivers/net/ethernet/smsc/smsc911x.c@@ -557,6 +557,7 @@ static int smsc911x_mii_read(struct mii_bus *bus, int phyaddr, int regidx) unsigned int addr; int i, reg; + pm_runtime_get_sync(bus->parent); spin_lock_irqsave(&pdata->mac_lock, flags); /* Confirm MII not busy */
@@ -582,6 +583,7 @@ static int smsc911x_mii_read(struct mii_bus *bus, int phyaddr, int regidx) out: spin_unlock_irqrestore(&pdata->mac_lock, flags); + pm_runtime_put(bus->parent); return reg; }
@@ -594,6 +596,7 @@ static int smsc911x_mii_write(struct mii_bus *bus, int phyaddr, int regidx, unsigned int addr; int i, reg; + pm_runtime_get_sync(bus->parent); spin_lock_irqsave(&pdata->mac_lock, flags); /* Confirm MII not busy */
@@ -623,6 +626,7 @@ static int smsc911x_mii_write(struct mii_bus *bus, int phyaddr, int regidx, out: spin_unlock_irqrestore(&pdata->mac_lock, flags); + pm_runtime_put(bus->parent); return reg; }
@@ -1589,6 +1593,8 @@ static int smsc911x_open(struct net_device *dev) int retval; int irq_flags; + pm_runtime_get_sync(dev->dev.parent); + /* find and start the given phy */ if (!dev->phydev) { retval = smsc911x_mii_probe(dev);
@@ -1735,6 +1741,7 @@ static int smsc911x_open(struct net_device *dev) phy_disconnect(dev->phydev); dev->phydev = NULL; out: + pm_runtime_put(dev->dev.parent); return retval; }
@@ -1766,6 +1773,7 @@ static int smsc911x_stop(struct net_device *dev) dev->phydev = NULL; } netif_carrier_off(dev); + pm_runtime_put(dev->dev.parent); SMSC_TRACE(pdata, ifdown, "Interface stopped"); return 0;
@@ -2334,7 +2342,6 @@ static int smsc911x_drv_remove(struct platform_device *pdev) free_netdev(dev); - pm_runtime_put(&pdev->dev); pm_runtime_disable(&pdev->dev); return 0;
@@ -2540,6 +2547,7 @@ static int smsc911x_drv_probe(struct platform_device *pdev) } spin_unlock_irq(&pdata->mac_lock); + pm_runtime_put(&pdev->dev); netdev_info(dev, "MAC Address: %pM\n", dev->dev_addr);
--
2.25.1