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

[Andy Fleming <afleming@freescale.com>]

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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