On Wed, Nov 21, 2012 at 10:00 AM, Alex Courbot <acourbot@xxxxxxxxxx> wrote: > On Wednesday 21 November 2012 16:48:45 Tomi Valkeinen wrote: >> If the power-off sequence disables a regulator that was supposed to be >> enabled by the power-on sequence (but wasn't enabled because of an >> error), the regulator_disable is still called when the driver runs the >> power-off sequence, isn't it? Regulator enables and disables are ref >> counted, and the enables should match the disables. > > And there collapses my theory. > >> > Failures might be better handled if sequences have some "recovery policy" >> > about what to do when they fail, as mentioned in the link above. As you >> > pointed out, the driver might not always know enough about the resources >> > involved to do the right thing. >> >> Yes, I think such recovery policy would be needed. > > Indeed, from your last paragraph this makes even more sense now. > > Oh, and I noticed I forgot to reply to this: > >> This I didn't understand. Doesn't "<&pwm 2 xyz>" point to a single >> device, no matter where and how many times it's used? > > That's true - however when dereferencing the phandle, the underlying framework > will try to acquire the PWM, which will result in failure if the same resource > is referenced several times. > > One could compare the phandles to avoid this, but in your example you must > know that for PWMs the "xyz" part is not relevant for comparison. > > This makes referencing of resources by name much easier to implement and more > elegant with respect to frameworks leveraging. I would rather (at least for how the DT bindings settle out) see the design separate the resource references from the sequence. ie. Declare which resources are used by a device's sequences all in one place and have the commands index into that. g. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
