[PATCH v1] vfio/mdev: Remove redundant driver match function

[PATCH v1] vfio/mdev: Remove redundant driver match function

[Lizhe]

If there is no driver match function, the driver core assumes that each
candidate pair (driver, device) matches, see driver_match_device().

Drop the bus's match function that always returned 1 and so
implements the same behaviour as when there is no match function.

Signed-off-by: Lizhe <sensor1010@163.com>
---
 drivers/vfio/mdev/mdev_driver.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 7825d83a55f8..fafa4416aad9 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -31,20 +31,10 @@ static void mdev_remove(struct device *dev)
 		drv->remove(to_mdev_device(dev));
 }
 
-static int mdev_match(struct device *dev, struct device_driver *drv)
-{
-	/*
-	 * No drivers automatically match. Drivers are only bound by explicit
-	 * device_driver_attach()
-	 */
-	return 0;
-}
-
 struct bus_type mdev_bus_type = {
 	.name		= "mdev",
 	.probe		= mdev_probe,
 	.remove		= mdev_remove,
-	.match		= mdev_match,
 };
 
 /**
-- 
2.34.1

Re: [PATCH v1] vfio/mdev: Remove redundant driver match function

[Alex Williamson]

On Sun, 19 Mar 2023 13:01:30 +0800
Lizhe <sensor1010@163.com> wrote:

> If there is no driver match function, the driver core assumes that each
> candidate pair (driver, device) matches, see driver_match_device().
> 
> Drop the bus's match function that always returned 1 and so
> implements the same behaviour as when there is no match function.

The removed function returns 0, not 1, so this is replacing the
functionality with something that does exactly the opposite of the
current behavior.  Please explain.  Thanks,

Alex
 
> Signed-off-by: Lizhe <sensor1010@163.com>
> ---
>  drivers/vfio/mdev/mdev_driver.c | 10 ----------
>  1 file changed, 10 deletions(-)
> 
> diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
> index 7825d83a55f8..fafa4416aad9 100644
> --- a/drivers/vfio/mdev/mdev_driver.c
> +++ b/drivers/vfio/mdev/mdev_driver.c
> @@ -31,20 +31,10 @@ static void mdev_remove(struct device *dev)
>  		drv->remove(to_mdev_device(dev));
>  }
>  
> -static int mdev_match(struct device *dev, struct device_driver *drv)
> -{
> -	/*
> -	 * No drivers automatically match. Drivers are only bound by explicit
> -	 * device_driver_attach()
> -	 */
> -	return 0;
> -}
> -
>  struct bus_type mdev_bus_type = {
>  	.name		= "mdev",
>  	.probe		= mdev_probe,
>  	.remove		= mdev_remove,
> -	.match		= mdev_match,
>  };
>  
>  /**