[PATCH v2] qe_lib: Set gpio data before changing the direction to output
Anton Vorontsov
avorontsov at ru.mvista.com
Wed Aug 19 07:33:55 EST 2009
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 at ruggedcom.com>
Acked-by: Anton Vorontsov <avorontsov at 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 at gmail.com
irc://irc.freenode.net/bd2
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