On Fri, Nov 26, 2021 at 10:43:48AM +0100, Johan Hovold wrote: > When generalising GPIO support and adding support for CP2102N, the GPIO > registration for some CP2105 devices accidentally broke. Specifically, > when all the pins of a port are in "modem" mode, and thus unavailable > for GPIO use, the GPIO chip would now be registered without having > initialised the number of GPIO lines. This would in turn be rejected by > gpiolib and some errors messages would be printed (but importantly probe > would still succeed). > > Fix this by initialising the number of GPIO lines before registering the > GPIO chip. > > Note that as for the other device types, and as when all CP2105 pins are > muxed for LED function, the GPIO chip is registered also when no pins > are available for GPIO use. > > Reported-by: Maarten Brock <m.brock@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/r/5eb560c81d2ea1a2b4602a92d9f48a89@xxxxxxxxxxxxx > Fixes: c8acfe0aadbe ("USB: serial: cp210x: implement GPIO support for CP2102N") > Cc: stable@xxxxxxxxxxxxxxx # 4.19 > Cc: Karoly Pados <pados@xxxxxxxx> > Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>