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usb: roles: don't get/set_role() when usb_role_switch is unregistered 

commit b787a3e781 upstream.

There is a possibility that usb_role_switch device is unregistered before
the user put usb_role_switch. In this case, the user may still want to
get/set_role() since the user can't sense the changes of usb_role_switch.

This will add a flag to show if usb_role_switch is already registered and
avoid unwanted behaviors.

Fixes: fde0aa6c17 ("usb: common: Small class for USB role switches")
cc: stable@vger.kernel.org
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240129093739.2371530-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Xu Yang 2024-01-29 17:37:39 +08:00 committed by Greg Kroah-Hartman
parent 0158216805
commit 2f414a56b3
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/usb/roles/class.c
View File

@ -21,6 +21,7 @@ struct usb_role_switch {
struct mutex lock; /* device lock*/
struct module *module; /* the module this device depends on */
enum usb_role role;
bool registered;
/* From descriptor */
struct device *usb2_port;
@ -47,6 +48,9 @@ int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)
if (IS_ERR_OR_NULL(sw))
return 0;
if (!sw->registered)
return -EOPNOTSUPP;
mutex_lock(&sw->lock);
ret = sw->set(sw, role);
@ -72,7 +76,7 @@ enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
{
enum usb_role role;
if (IS_ERR_OR_NULL(sw))
if (IS_ERR_OR_NULL(sw) || !sw->registered)
return USB_ROLE_NONE;
mutex_lock(&sw->lock);
@ -356,6 +360,8 @@ usb_role_switch_register(struct device *parent,
return ERR_PTR(ret);
}
sw->registered = true;
/* TODO: Symlinks for the host port and the device controller. */
return sw;
@ -370,8 +376,10 @@ EXPORT_SYMBOL_GPL(usb_role_switch_register);
*/
void usb_role_switch_unregister(struct usb_role_switch *sw)
{
if (!IS_ERR_OR_NULL(sw))
if (!IS_ERR_OR_NULL(sw)) {
sw->registered = false;
device_unregister(&sw->dev);
}
}
EXPORT_SYMBOL_GPL(usb_role_switch_unregister);