On Thu, Mar 21, 2019 at 12:17 PM Daniel Thompson <daniel.thomp...@linaro.org> wrote: > On Wed, Mar 20, 2019 at 05:29:56PM +0000, Russell King - ARM Linux admin > wrote: > > On Wed, Mar 20, 2019 at 12:26:58PM +0530, Manivannan Sadhasivam wrote:
> > That said, if a reset line is shared between multiple devices, and a > > driver wants to assert the reset line, it would disrupt the operation > > of all those devices, so there would need to be some kind of > > synchronisation between the drivers. > > That is what shared ownership of the reset line provides. When a line is > shared a single driver does not have the authority to unilaterally > assert reset because deasserts and asserts are counted and the line only > goes high again when they balance. This is what we want for this I'm pretty sure. Regulators have the same thing with internal reference counting so that if you turn a shared regulator on from several clients it just increases the refcount and it will not really be turned off until the last consumer is disabling it. Yours, Linus Walleij
