Re: [PATCH v2] qe_lib: Set gpio data before changing the direction to output

[Anton Vorontsov <avorontsov@ru.mvista.com>]

On Tue, Aug 18, 2009 at 05:20:44PM -0400, Michael Barkowski wrote:
> This avoids having a short glitch if the desired initial value is not
> the same as what was previously in the data register.
> 
> Signed-off-by: Michael Barkowski <michaelbarkowski@ruggedcom.com>

Acked-by: Anton Vorontsov <avorontsov@ru.mvista.com>

Thanks!

> ---
> Anton Vorontsov wrote:
> > There is a recursive locking bug: _set() takes the same spinlock.
> > So you'd better move this call two lines upper. Otherwise the
> > patch looks OK.
> > 
> > Thanks!
> 
> Thanks - here is v2.
> 
>  arch/powerpc/sysdev/qe_lib/gpio.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/sysdev/qe_lib/gpio.c b/arch/powerpc/sysdev/qe_lib/gpio.c
> index 3485288..8e7a776 100644
> --- a/arch/powerpc/sysdev/qe_lib/gpio.c
> +++ b/arch/powerpc/sysdev/qe_lib/gpio.c
> @@ -105,14 +105,14 @@ static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
>  	struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc);
>  	unsigned long flags;
>  
> +	qe_gpio_set(gc, gpio, val);
> +
>  	spin_lock_irqsave(&qe_gc->lock, flags);
>  
>  	__par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_OUT, 0, 0, 0);
>  
>  	spin_unlock_irqrestore(&qe_gc->lock, flags);
>  
> -	qe_gpio_set(gc, gpio, val);
> -
>  	return 0;
>  }
>  
> -- 
> 1.6.3.3
> 

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2