Re: wrong driver remove order

[Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>]

On Mon, 17 Nov 2008 22:04:17 +0100, Jean Delvare wrote:
> Hi Guennadi,
> 
> On Thu, 30 Oct 2008 15:13:14 +0100 (CET), Guennadi Liakhovetski wrote:
> > Hi,
> > 
> > I have two i2c modules, one of which uses the other one: a camera and a 
> > GPIO-extender, and the camera uses a GPIO from that extender. I first load 
> > the GPIO-extender driver (pca953x.c), then the camera (mt9m001.c), then as 
> > I tried to remove the bus driver (i2c-mxc, not yet in the mainline), first 
> > the GPIO-extender's .remove() method has been called, which, of course, 
> > failed, because mt9m001 was still holding its GPIO... AFAIU, the remove 
> > order should be reverse from probe, right?
> 
> It would indeed make sense for the removal order to be the reverse of
> the bind order. Can you please try the following patch and report if it
> solves your problem?

Any news from this? I'd like to push this change to Linus this week if
it actually solves your problem.

> From: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Subject: i2c: Remove i2c clients in reverse order
> 
> i2c clients should be removed in reverse order compared to the probe
> (actually: bind) order. This matters when several clients depend on
> each other.
> 
> Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Cc: Guennadi Liakhovetski <g.liakhovetski-Mmb7MZpHnFY@public.gmane.org>
> ---
>  drivers/i2c/i2c-core.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- linux-2.6.28-rc5.orig/drivers/i2c/i2c-core.c	2008-11-17 21:29:59.000000000 +0100
> +++ linux-2.6.28-rc5/drivers/i2c/i2c-core.c	2008-11-17 21:44:06.000000000 +0100
> @@ -631,7 +631,7 @@ int i2c_del_adapter(struct i2c_adapter *
>  
>  	/* detach any active clients. This must be done first, because
>  	 * it can fail; in which case we give up. */
> -	list_for_each_entry_safe(client, _n, &adap->clients, list) {
> +	list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) {
>  		struct i2c_driver	*driver;
>  
>  		driver = client->driver;

-- 
Jean Delvare