[i2c] [PATCH] i2c: Keep client->driver and client->dev.driver in sync

[David Brownell]

On Saturday 08 March 2008, Jean Delvare wrote:
> From: Hans Verkuil <hverkuil at xs4all.nl>
> 
> Ensures that client->driver is set to NULL if the probe() returns an
> error (this keeps client->driver and client->dev.driver in sync).
> 
> Signed-off-by: Hans Verkuil <hverkuil at xs4all.nl>
> Signed-off-by: Jean Delvare <khali at linux-fr.org>
> ---
> Hans, I've updated your patch a bit to make i2c_device_probe() look
> more like i2c_device_remove(); hope you don't mind.
> 
> David, this fix looks correct to me, I'll send it to Linus quickly if
> you have no objection.

The only issue I have is that code which the driver probe()
calls may expect client->driver to be set, but it won't be...

While I'd rather see client->driver vanish, in this case I'd
just suggest leaving the early assignment, and nulling it out
on error (instead of assigning it on success).


>  drivers/i2c/i2c-core.c |    7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> --- linux-2.6.25-rc4.orig/drivers/i2c/i2c-core.c	2008-03-08 17:57:52.000000000 +0100
> +++ linux-2.6.25-rc4/drivers/i2c/i2c-core.c	2008-03-08 21:43:11.000000000 +0100
> @@ -90,12 +90,15 @@ static int i2c_device_probe(struct devic
>  {
>  	struct i2c_client	*client = to_i2c_client(dev);
>  	struct i2c_driver	*driver = to_i2c_driver(dev->driver);
> +	int status;
>  
>  	if (!driver->probe)
>  		return -ENODEV;
> -	client->driver = driver;
>  	dev_dbg(dev, "probe\n");
> -	return driver->probe(client);
> +	status = driver->probe(client);
> +	if (status == 0)
> +		client->driver = driver;
> +	return status;
>  }
>  
>  static int i2c_device_remove(struct device *dev)
> 
> 
> -- 
> Jean Delvare
>