On Mon, Jul 21, 2014 at 8:12 PM, Guenter Roeck <[email protected]> wrote:
> The gpio include file and the gpio documentation declare and document > GPIOF_ACTIVE_LOW as one of the flags to be passed to gpio_request_one > and related functions. However, the flag is not evaluated or used. > > This can cause problems in at least two areas: First, the same API can > be used to auto-export pins to user space. The missing support for > GPIOF_ACTIVE_LOW results in unexpected behavior for such auto-exported > pins. Second, the requested gpio pin can be convered for use by > gpiod functions with gpio_to_desc(). While gpio API functions do not > support GPIOF_ACTIVE_LOW, gpiod functions do, which again results in > unexpected behavior. > > Check the flag in gpio_request_one and set the gpio internal flag > FLAG_ACTIVE_LOW if it is set to address those problems. > > Signed-off-by: Guenter Roeck <[email protected]> > Reviewed-by: Alexandre Courbot <[email protected]> Patch applied after manually rebasing so it hits gpiolib-legacy.c. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
