Re: [RFC PATCH 2/4] power: reset: reboot-mode: Wire reboot_mode enum to magic

[Elliot Berman]

On 7/25/2023 3:03 AM, Mukesh Ojha wrote:
> On 7/25/2023 4:00 AM, Elliot Berman wrote:
> > Allow the reboot mode type to be wired to magic.
> >
> > Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
> > ---
> >   drivers/power/reset/reboot-mode.c | 30 ++++++++++++++++++++++++++----
> >   1 file changed, 26 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/power/reset/reboot-mode.c 
> > b/drivers/power/reset/reboot-mode.c
> > index a646aefa041b..4ea97ccbaf51 100644
> > --- a/drivers/power/reset/reboot-mode.c
> > +++ b/drivers/power/reset/reboot-mode.c
> > @@ -22,12 +22,8 @@ struct mode_info {
> >   static bool get_reboot_mode_magic(struct reboot_mode_driver *reboot,
> >                         const char *cmd, unsigned int *magic)
> >   {
> > -    const char *normal = "normal";
> >       struct mode_info *info;
> > -    if (!cmd)
> > -        cmd = normal;
> > -
> >       list_for_each_entry(info, &reboot->head, list) {
> >           if (!strcmp(info->mode, cmd)) {
> >               *magic = info->magic;
> > @@ -45,6 +41,32 @@ static int reboot_mode_notify(struct notifier_block 
> > *this,
> >       unsigned int magic;
> >       reboot = container_of(this, struct reboot_mode_driver, 
> > reboot_notifier);
> > +
> > +    if (!cmd) {
> > +        switch (mode) {
>
> IIUC, mode will be filled up with reboot_mode during restart
> notifier and not reboot notifiers ?

Ah, you're correct. I should register a restart notifier and not use 
reboot mode framework. I'll follow similar bindings.

> > +        case REBOOT_COLD:
> > +            cmd = "cold";
> > +            break;
> > +        case REBOOT_WARM:
> > +            cmd = "warm";
> > +            break;
> > +        case REBOOT_HARD:
> > +            cmd = "hard";
> > +            break;
> > +        case REBOOT_SOFT:
> > +            cmd = "soft";
> > +            break;
> > +        case REBOOT_GPIO:
> > +            cmd = "gpio";
>
> These strings are already there kernel/reboot.c
> Can it be reused ?
>
> #define REBOOT_COLD_STR         "cold"
> #define REBOOT_WARM_STR         "warm"
> #define REBOOT_HARD_STR         "hard"
> #define REBOOT_SOFT_STR         "soft"
> #define REBOOT_GPIO_STR         "gpio"
> #define REBOOT_UNDEFINED_STR    "undefined"

One set of constants are "binding" for devicetree and the other is for 
sysfs. I think they should be kept separate.

> > +            break;
> > +        }
> > +        if (get_reboot_mode_magic(reboot, cmd, &magic)) {
>
> Is info->mode is going to filled up with mode-cold, mode-warm and so
> on from DT to compare against cmd?
>
> What if , cmd is not among the one above switch, NULL pointer during
> strcmp ?
> > -Mukesh
>
> > +            reboot->write(reboot, magic);
> > +            return NOTIFY_DONE;
> > +        }
> > +        cmd = "normal";
> > +    }
> > +
> >       if (get_reboot_mode_magic(reboot, cmd, &magic))
> >           reboot->write(reboot, magic);