2021-01-18 15:21:21

by Geert Uytterhoeven

Subject: [PATCH] net: smsc911x: Make Runtime PM handling more fine-grained

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 <[email protected]>
---
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

2021-01-20 01:54:40

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] net: smsc911x: Make Runtime PM handling more fine-grained

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Mon, 18 Jan 2021 16:08:57 +0100 you wrote:
> 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.
>
> [...]

Here is the summary with links:
- net: smsc911x: Make Runtime PM handling more fine-grained
https://git.kernel.org/netdev/net-next/c/1e30b8d755b8

You are awesome, thank you!
--
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