On Wed, Dec 02, 2020 at 07:08:47PM -0800, Prashant Malani wrote: > Add the Type C bus for plug alternate modes which are being > registered via the Type C connector class. This ensures that udev events > get generated when plug alternate modes are registered (and not just for > partner/port alternate modes), even though the Type C bus doesn't link > plug alternate mode devices to alternate mode drivers. I still don't understand how is the uevent related to the bus? If you check the device_add() function, on line 2917, kobject_uevent() is called unconditionally. The device does not need a bus for that event to be generated. Also, I don't understand how are the cable plug alt modes now prevented from being bind to the alt mode drivers? > Update the Type C bus documentation to mention that there > are alternate mode devices for plugs as well. > > Signed-off-by: Prashant Malani <pmalani@xxxxxxxxxxxx> > Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > --- > Documentation/driver-api/usb/typec_bus.rst | 6 +++--- > drivers/usb/typec/class.c | 8 ++++++-- > 2 files changed, 9 insertions(+), 5 deletions(-) > > diff --git a/Documentation/driver-api/usb/typec_bus.rst b/Documentation/driver-api/usb/typec_bus.rst > index 21c890ae17e5..7874d2f37d9f 100644 > --- a/Documentation/driver-api/usb/typec_bus.rst > +++ b/Documentation/driver-api/usb/typec_bus.rst > @@ -15,9 +15,9 @@ modes by using the SVID and the mode number. > > :ref:`USB Type-C Connector Class <typec>` provides a device for every alternate > mode a port supports, and separate device for every alternate mode the partner > -supports. The drivers for the alternate modes are bound to the partner alternate > -mode devices, and the port alternate mode devices must be handled by the port > -drivers. > +or cable plug supports. The drivers for the alternate modes are bound to the > +partner alternate mode devices, and the port alternate mode devices must be > +handled by the port drivers. > > When a new partner alternate mode device is registered, it is linked to the > alternate mode device of the port that the partner is attached to, that has > diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c > index 35eec707cb51..74061a699f16 100644 > --- a/drivers/usb/typec/class.c > +++ b/drivers/usb/typec/class.c > @@ -478,8 +478,12 @@ typec_register_altmode(struct device *parent, > if (!is_port) > typec_altmode_set_partner(alt); > > - /* The partners are bind to drivers */ > - if (is_typec_partner(parent)) > + /* > + * The partners are bind to drivers. > + * Also set the bus field for plug alt modes so that the udev event occurs on device > + * registration. > + */ > + if (is_typec_partner(parent) || is_typec_plug(parent)) > alt->adev.dev.bus = &typec_bus; > > ret = device_register(&alt->adev.dev); > -- > 2.29.2.454.gaff20da3a2-goog thanks, -- heikki
