On Fri, Dec 4, 2020 at 5:47 PM Marc Zyngier <maz@xxxxxxxxxx> wrote: > When reporting the state of a GPIO to userspace, we never check > for the actual validity of the line, meaning we report invalid > lines as being usable. A subsequent request will fail though, > which is an inconsistent behaviour from a userspace perspective. > > Instead, let's check for the validity of the line and report it > as used if it is invalid. This allows a tool such as gpioinfo > to report something sensible: > > gpiochip3 - 4 lines: > line 0: unnamed unused input active-high > line 1: unnamed kernel input active-high [used] > line 2: unnamed kernel input active-high [used] > line 3: unnamed unused input active-high > > In this example, lines 1 and 2 are invalid, and cannot be used by > userspace. > > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> This makes sense, so patch applied (unless Bartosz tells me otherwise, then I'll pull it out again). Yours, Linus Walleij
