Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 7 Jan 2021 10:17:38 +0100 | From | Greg KH <> | Subject | Re: [PATCH] usb: typec: Send uevent for num_altmodes update |
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On Wed, Jan 06, 2021 at 07:49:04PM -0800, Prashant Malani wrote: > Generate a change uevent when the "number_of_alternate_modes" sysfs file > for partners and plugs is updated by a port driver. > > Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> > Cc: Benson Leung <bleung@chromium.org> > Signed-off-by: Prashant Malani <pmalani@chromium.org> > --- > drivers/usb/typec/class.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c > index ebfd3113a9a8..8f77669f9cf4 100644 > --- a/drivers/usb/typec/class.c > +++ b/drivers/usb/typec/class.c > @@ -766,6 +766,7 @@ int typec_partner_set_num_altmodes(struct typec_partner *partner, int num_altmod > return ret; > > sysfs_notify(&partner->dev.kobj, NULL, "number_of_alternate_modes"); > + kobject_uevent(&partner->dev.kobj, KOBJ_CHANGE);
Shouldn't the sysfs_notify() handle the "something has changed" logic good enough for userspace, as obviously someone is polling on the thing (otherwise we wouldn't be calling sysfs_notify...)
The kobject itself hasn't "changed", but rather an individual attribute has changed. We don't want to create uevents for every individual sysfs attribute changing values, do we?
What is preventing a normal "monitor the sysfs file" logic from working here for anyone who wants to know that the alternate modes have changed?
thanks,
greg k-h
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