Re: [PATCH 1/6] usb: musb: Fix broken use of static variable for multiple instances

[Bin Liu <b-liu-l0cyMroinI0@public.gmane.org>]

Hi,

On Fri, Nov 11, 2016 at 10:42:57AM -0800, Tony Lindgren wrote:
> We can't use static variable first for checking when musb is
> initialized when we have multiple musb instances like on am335x.
> 
> Tested-by: Ladislav Michl <ladis-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
> Reviewed-by: Johan Hovold <johan-UKKVnA4tBMC5azolltMz9laTQe2KTcn/@public.gmane.org>
> Tested-by: Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
> Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
> ---
>  drivers/usb/musb/musb_core.c | 9 +++++----
>  drivers/usb/musb/musb_core.h | 2 ++
>  2 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -2291,6 +2291,7 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
>  	if (status)
>  		goto fail5;
>  
> +	musb->is_initialized = 1;
>  	pm_runtime_mark_last_busy(musb->controller);
>  	pm_runtime_put_autosuspend(musb->controller);
>  
> @@ -2629,7 +2630,6 @@ static int musb_runtime_suspend(struct device *dev)
>  static int musb_runtime_resume(struct device *dev)
>  {
>  	struct musb	*musb = dev_to_musb(dev);
> -	static int	first = 1;
>  
>  	/*
>  	 * When pm_runtime_get_sync called for the first time in driver
> @@ -2640,9 +2640,10 @@ static int musb_runtime_resume(struct device *dev)
>  	 * Also context restore without save does not make
>  	 * any sense
>  	 */
> -	if (!first)
> -		musb_restore_context(musb);
> -	first = 0;
> +	if (!musb->is_initialized)
> +		return 0;
> +
> +	musb_restore_context(musb);
>  
>  	if (musb->need_finish_resume) {
>  		musb->need_finish_resume = 0;
> diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
> --- a/drivers/usb/musb/musb_core.h
> +++ b/drivers/usb/musb/musb_core.h
> @@ -385,6 +385,8 @@ struct musb {
>  	int			a_wait_bcon;	/* VBUS timeout in msecs */
>  	unsigned long		idle_timeout;	/* Next timeout in jiffies */
>  
> +	unsigned		is_initialized:1;
> +

The musb strcut is getting bigger and bigger. Is it possible to not add
a new variable but use one initialized in musb_init_controller() for
this flag purpose? Readability shouldn't be an issue, since it is only
used once in musb_runtime_resume().

Sorry I missed if this patch has been sent before.

Regards,
-Bin.

>  	/* active means connected and not suspended */
>  	unsigned		is_active:1;
>  
> -- 
> 2.10.2
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