Re: [PATCH] gpio: gpiolib: make gpio_bus_type const

From: Ricardo B. Marliere
Date: Sun Feb 04 2024 - 14:41:41 EST


Hi Bartosz,

On 4 Feb 19:34, Bartosz Golaszewski wrote:
> On Sun, Feb 4, 2024 at 5:29 PM Ricardo B. Marliere <ricardo@xxxxxxxxxxxx> wrote:
> >
> > Now that the driver core can properly handle constant struct bus_type,
> > move the gpio_bus_type variable to be a constant structure as well,
> > placing it into read-only memory which can not be modified at runtime.
> >
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>
> > ---
> > drivers/gpio/gpiolib.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> > index d50a786f8176..24d046268a01 100644
> > --- a/drivers/gpio/gpiolib.c
> > +++ b/drivers/gpio/gpiolib.c
> > @@ -63,7 +63,7 @@ static int gpio_bus_match(struct device *dev, struct device_driver *drv)
> > return 1;
> > }
> >
> > -static struct bus_type gpio_bus_type = {
> > +static const struct bus_type gpio_bus_type = {
> > .name = "gpio",
> > .match = gpio_bus_match,
> > };
> >
> > ---
> > base-commit: 3eac8bbed22e940ac1645a884f221bef408f675c
> > change-id: 20240204-bus_cleanup-gpio-57eea8d32a5a
> >
> > Best regards,
> > --
> > Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>
> >
>
> Ha! Does the same work now for struct device_type?

>From a quick grep it seems to be the case, but maybe you should wait for
Greg for confirmation. Also found this:
https://lore.kernel.org/all/1305850262-9575-5-git-send-email-gregkh@xxxxxxx/

Best regards,
- Ricardo.



>
> Because I just sent this:
> https://lore.kernel.org/linux-gpio/20240201162758.50733-1-brgl@xxxxxxxx/
>
> And maybe I should make it const right away.
>
> Bart