Hi Jaya, > >> +[OPTIONAL] Spinlock-Safe GPIO Batch access > > Is it really spinlock safe in general? Or only if gpio_cansleep(gpio) > > if false for each gpio to get or set? > > You are correct to raise this issue. It is only spinlock safe if > chip->cansleep is false. Initially, I wasn't sure what to do. The > original gpio set/get_value() just does; > WARN_ON(extra_checks && chip->can_sleep); > and it is documented as: > > " > Spinlock-Safe GPIO access > ------------------------- > <snip> > return zero. Also, using these calls for GPIOs that can't safely be accessed > without sleeping (see below) is an error. > " > > I will change this in the batch code to return an error if can_sleep > is detected on any involved gpio_chip. Wait, I got it wrong. I thought gpio_set_value might sleep if chip->cansleep is true, but there are extra API functions for cansleep-chips. So I'd do it the same way as for the non-batch functions and just WARN_ON(extra_checks && chip->cansleep) for each involved chip.
Later it might make sense to add the _cansleep variants. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Strasse 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
