From: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx> [ Upstream commit 3e63cff384e625f09758ce8f4d01ae3033402b63 ] Right now we don't report to user-space a role switch when doing a usb_role_switch_set_role() despite having registered the uevent callbacks. This patch switches on the notifications allowing user-space to see role-switch change notifications and subsequently determine the current controller data-role. example: PFX=/devices/platform/soc/78d9000.usb/ci_hdrc.0 root@somebox# udevadm monitor -p KERNEL[49.894994] change $PFX/usb_role/ci_hdrc.0-role-switch (usb_role) ACTION=change DEVPATH=$PFX/usb_role/ci_hdrc.0-role-switch SUBSYSTEM=usb_role DEVTYPE=usb_role_switch USB_ROLE_SWITCH=ci_hdrc.0-role-switch SEQNUM=2432 Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx> Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> Cc: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx> Cc: chenqiwu <chenqiwu@xxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200508162937.2566818-1-bryan.odonoghue@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/usb/roles/class.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c index 5b17709821df..27d92af29635 100644 --- a/drivers/usb/roles/class.c +++ b/drivers/usb/roles/class.c @@ -49,8 +49,10 @@ int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role) mutex_lock(&sw->lock); ret = sw->set(sw, role); - if (!ret) + if (!ret) { sw->role = role; + kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE); + } mutex_unlock(&sw->lock); -- 2.25.1
