[PATCH 28/46] PHY: remove rwsem use from phy core

[PATCH 28/46] PHY: remove rwsem use from phy core

[Greg Kroah-Hartman]

The subsystem rwsem is not used by the driver core at all, so the use of
it in the phy code doesn't make any sense.  They might possibly
want to use a local lock, but I am unsure about that.

Cc: netdev <netdev@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/net/phy/fixed.c      |    6 ------
 drivers/net/phy/phy_device.c |    9 +--------
 2 files changed, 1 insertions(+), 14 deletions(-)

diff --git a/drivers/net/phy/fixed.c b/drivers/net/phy/fixed.c
index 66da91b..68c99b4 100644
--- a/drivers/net/phy/fixed.c
+++ b/drivers/net/phy/fixed.c
@@ -276,21 +276,15 @@ static int fixed_mdio_register_device(int number, int speed, int duplex)
 	   artificially, we are binding the driver here by hand;
 	   it will be the same for all the fixed phys anyway.
 	 */
-	down_write(&phydev->dev.bus->subsys.rwsem);
-
 	phydev->dev.driver = &fixed_mdio_driver.driver;
 
 	err = phydev->dev.driver->probe(&phydev->dev);
 	if(err < 0) {
 		printk(KERN_ERR "Phy %s: problems with fixed driver\n",phydev->dev.bus_id);
-		up_write(&phydev->dev.bus->subsys.rwsem);
 		goto probe_fail;
 	}
 
 	err = device_bind_driver(&phydev->dev);
-
-	up_write(&phydev->dev.bus->subsys.rwsem);
-
 	if (err)
 		goto probe_fail;
 
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 7d5b6d1..8f01952 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -208,16 +208,12 @@ struct phy_device *phy_attach(struct net_device *dev,
 	 * exist, and we should use the genphy driver. */
 	if (NULL == d->driver) {
 		int err;
-		down_write(&d->bus->subsys.rwsem);
 		d->driver = &genphy_driver.driver;
 
 		err = d->driver->probe(d);
-
 		if (err >= 0)
 			err = device_bind_driver(d);
 
-		up_write(&d->bus->subsys.rwsem);
-
 		if (err)
 			return ERR_PTR(err);
 	}
@@ -258,11 +254,8 @@ void phy_detach(struct phy_device *phydev)
 	 * was using the generic driver), we unbind the device
 	 * from the generic driver so that there's a chance a
 	 * real driver could be loaded */
-	if (phydev->dev.driver == &genphy_driver.driver) {
-		down_write(&phydev->dev.bus->subsys.rwsem);
+	if (phydev->dev.driver == &genphy_driver.driver)
 		device_release_driver(&phydev->dev);
-		up_write(&phydev->dev.bus->subsys.rwsem);
-	}
 }
 EXPORT_SYMBOL(phy_detach);
 
-- 
1.5.1.2

Re: [PATCH 28/46] PHY: remove rwsem use from phy core

[Andy Fleming]

On Apr 27, 2007, at 13:53, Greg Kroah-Hartman wrote:

> The subsystem rwsem is not used by the driver core at all, so the  
> use of
> it in the phy code doesn't make any sense.  They might possibly
> want to use a local lock, but I am unsure about that.
>
> Cc: netdev <netdev@vger.kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Acked-by: Andy Fleming <afleming@freescale.com>

> ---

I think I copied that code from elsewhere without truly understanding  
it.

*bows head in shame*

As such, I have no objection to this patch unless someone says it  
breaks their board.  :)

>  drivers/net/phy/fixed.c      |    6 ------
>  drivers/net/phy/phy_device.c |    9 +--------
>  2 files changed, 1 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/phy/fixed.c b/drivers/net/phy/fixed.c
> index 66da91b..68c99b4 100644
> --- a/drivers/net/phy/fixed.c
> +++ b/drivers/net/phy/fixed.c
> @@ -276,21 +276,15 @@ static int fixed_mdio_register_device(int  
> number, int speed, int duplex)
>  	   artificially, we are binding the driver here by hand;
>  	   it will be the same for all the fixed phys anyway.
>  	 */
> -	down_write(&phydev->dev.bus->subsys.rwsem);
> -
>  	phydev->dev.driver = &fixed_mdio_driver.driver;
>
>  	err = phydev->dev.driver->probe(&phydev->dev);
>  	if(err < 0) {
>  		printk(KERN_ERR "Phy %s: problems with fixed driver\n",phydev- 
> >dev.bus_id);
> -		up_write(&phydev->dev.bus->subsys.rwsem);
>  		goto probe_fail;
>  	}
>
>  	err = device_bind_driver(&phydev->dev);
> -
> -	up_write(&phydev->dev.bus->subsys.rwsem);
> -
>  	if (err)
>  		goto probe_fail;
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/ 
> phy_device.c
> index 7d5b6d1..8f01952 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -208,16 +208,12 @@ struct phy_device *phy_attach(struct  
> net_device *dev,
>  	 * exist, and we should use the genphy driver. */
>  	if (NULL == d->driver) {
>  		int err;
> -		down_write(&d->bus->subsys.rwsem);
>  		d->driver = &genphy_driver.driver;
>
>  		err = d->driver->probe(d);
> -
>  		if (err >= 0)
>  			err = device_bind_driver(d);
>
> -		up_write(&d->bus->subsys.rwsem);
> -
>  		if (err)
>  			return ERR_PTR(err);
>  	}
> @@ -258,11 +254,8 @@ void phy_detach(struct phy_device *phydev)
>  	 * was using the generic driver), we unbind the device
>  	 * from the generic driver so that there's a chance a
>  	 * real driver could be loaded */
> -	if (phydev->dev.driver == &genphy_driver.driver) {
> -		down_write(&phydev->dev.bus->subsys.rwsem);
> +	if (phydev->dev.driver == &genphy_driver.driver)
>  		device_release_driver(&phydev->dev);
> -		up_write(&phydev->dev.bus->subsys.rwsem);
> -	}
>  }
>  EXPORT_SYMBOL(phy_detach);
>
> -- 
> 1.5.1.2
>
> -
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