6.1-stable review patch. If anyone has any objections, please let me know.
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From: Roy Luo royluo@google.com
[ Upstream commit 0ef40f399aa2be8c04aee9b7430705612c104ce5 ]
udc device and gadget device are tightly coupled, yet there's no good way to corelate the two. Add a sysfs link in udc that points to the corresponding gadget device. An example use case: userspace configures a f_midi configfs driver and bind the udc device, then it tries to locate the corresponding midi device, which is a child device of the gadget device. The gadget device that's associated to the udc device has to be identified in order to index the midi device. Having a sysfs link would make things much easier.
Signed-off-by: Roy Luo royluo@google.com Link: https://lore.kernel.org/r/20240307030922.3573161-1-royluo@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Stable-dep-of: 399a45e5237c ("usb: gadget: core: flush gadget workqueue after device removal") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/udc/core.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 6d7f8e98ba2a8..5085580eeb3ad 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1419,8 +1419,16 @@ int usb_add_gadget(struct usb_gadget *gadget) if (ret) goto err_free_id;
+ ret = sysfs_create_link(&udc->dev.kobj, + &gadget->dev.kobj, "gadget"); + if (ret) + goto err_del_gadget; + return 0;
+ err_del_gadget: + device_del(&gadget->dev); + err_free_id: ida_free(&gadget_id_numbers, gadget->id_number);
@@ -1529,6 +1537,7 @@ void usb_del_gadget(struct usb_gadget *gadget) mutex_unlock(&udc_lock);
kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); + sysfs_remove_link(&udc->dev.kobj, "gadget"); flush_work(&gadget->work); device_del(&gadget->dev); ida_free(&gadget_id_numbers, gadget->id_number);