Re: [PATCH] watchdog: Report firmware_version in sysfs

[Guenter Roeck]

On 11/25/22 17:00, Thomas Weißschuh wrote:
> On 2022-11-25 16:37-0800, Guenter Roeck wrote:
> > On 11/25/22 14:23, Thomas Weißschuh wrote:
> > > This synchronizes the information reported by ioctl and sysfs.
> > > The mismatch is confusing because "wdctl" from util-linux uses the ioctl
> > > when used with root privileges and sysfs without.
> > >
> > > Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
> > >
> > > ---
> > >
> > > Userspace implementation:
> > >
> > > https://github.com/util-linux/util-linux/pull/1927
> > > ---
> > >    drivers/watchdog/watchdog_dev.c | 10 ++++++++++
> > >    1 file changed, 10 insertions(+)
> > >
> > > diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
> > > index 55574ed42504..88c76e27873c 100644
> > > --- a/drivers/watchdog/watchdog_dev.c
> > > +++ b/drivers/watchdog/watchdog_dev.c
> > > @@ -555,6 +555,15 @@ static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
> > >    }
> > >    static DEVICE_ATTR_RO(identity);
> > > +static ssize_t firmware_version_show(struct device *dev, struct device_attribute *attr,
> > > +				     char *buf)
> > > +{
> > > +	struct watchdog_device *wdd = dev_get_drvdata(dev);
> > > +
> > > +	return sysfs_emit(buf, "%d\n", wdd->info->firmware_version);
> > > +}
> > > +static DEVICE_ATTR_RO(firmware_version);
> > > +
> > >    static ssize_t state_show(struct device *dev, struct device_attribute *attr,
> > >    				char *buf)
> > >    {
> > > @@ -618,6 +627,7 @@ static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
> > >    static struct attribute *wdt_attrs[] = {
> > >    	&dev_attr_state.attr,
> > >    	&dev_attr_identity.attr,
> > > +	&dev_attr_firmware_version.attr,
> > >    	&dev_attr_timeout.attr,
> > >    	&dev_attr_min_timeout.attr,
> > >    	&dev_attr_max_timeout.attr,
> > >
> > > base-commit: 0b1dcc2cf55ae6523c6fbd0d741b3ac28c9f4536
> >
> > I think this conflicts with drivers/watchdog/ziirave_wdt.c which generates its own
> > firmnware_version attribute.
>
> Indeed, thanks for the catch.
>
> We probably can't change the attribute from ziirave_wdt, which is a bit
> unfortunate as "firmware_version" would nicely match the name from
> "struct watchdog_info".
>
> How about "fw_version"?

I don't have a better idea. Go for it.

Guenter

> That would match the naming of sysfs attributes from a bunch of other
> subsystems.
>
> And obviously an addition to Documentation/ABI/testing/sysfs-class-watchdog is
> also missing from the patch.
> I'll add it in v2.
>
> Thomas