Hello Dmitry, On Fri, May 24, 2024 at 02:42:04PM +0300, Dmitry Baryshkov wrote: > On Fri, May 24, 2024 at 01:31:58PM +0200, Francesco Dolcini wrote: > > On Fri, May 24, 2024 at 12:56:15PM +0300, Dmitry Baryshkov wrote: > > > On Fri, May 24, 2024 at 09:10:34AM +0200, Francesco Dolcini wrote: > > > > From: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx> > > > > > > > > The enable gpio is not required when the SBU mux is used only for > > > > orientation, make it optional. > > > > > > > > Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx> > > > > --- > > > > drivers/usb/typec/mux/gpio-sbu-mux.c | 11 ++++++++--- > > > > 1 file changed, 8 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/usb/typec/mux/gpio-sbu-mux.c b/drivers/usb/typec/mux/gpio-sbu-mux.c > > > > index 374168482d36..cf44259980a1 100644 > > > > --- a/drivers/usb/typec/mux/gpio-sbu-mux.c > > > > +++ b/drivers/usb/typec/mux/gpio-sbu-mux.c > > ... > > > > @@ -66,6 +66,9 @@ static int gpio_sbu_mux_set(struct typec_mux_dev *mux, > > > > { > > > > struct gpio_sbu_mux *sbu_mux = typec_mux_get_drvdata(mux); > > > > > > > > + if (!sbu_mux->enable_gpio) > > > > + return -EOPNOTSUPP; > > > > > > Can we skip registering the mux if there is no enable_gpio? This can > > > save users from the unexpected errors during runtime. > > > > Yes, I considered this option. > > > > The rationale for the current implementation is that if the device tree is > > correct (no mode-switch property, when enable-gpios is not present), nobody > > will call gpio_sbu_mux_set() so no runtime error is possible. If the > > configuration in the DT is not correct you get this runtime error. > > > > With your proposal in case the DT configuration is not correct there will be no > > errors from the kernel, but the functionality will not work. > > I'm slightly biased maybe, but I prefer an error from probe (or > dependent devices being deferred). On the other hand, current motto is > that 'the kernel should not duplicate dt-validate's work'. I am in favor of "the kernel should not duplicate dt-validate's work". Now the question is if you are ok with the current implementation or you want me to change the way you suggested. Or maybe there is a third variant, not doing the return -EOPNOTSUPP and registering gpio_sbu_mux_set() even if the gpio get returns NULL. This is a one-line patch and everything will work just fine. Francesco