kernel/linux.git/drivers/usb/roles, branch v6.19.11

usb: roles: get usb role switch from parent only for usb-b-connector

2026-03-19T15:15:04+00:00

commit 8345b1539faa49fcf9c9439c3cbd97dac6eca171 upstream. usb_role_switch_is_parent() was walking up to the parent node and checking for the "usb-role-switch" property regardless of the type of the passed fwnode. This could cause unrelated device nodes to be probed as potential role switch parent, leading to spurious matches and "-EPROBE_DEFER" being returned infinitely. Till now only Type-B connector node will have a parent node which may present "usb-role-switch" property and register the role switch device. For Type-C connector node, its parent node will always be a Type-C chip device which will never register the role switch device. However, it may still present a non-boolean "usb-role-switch = <&usb_controller>" property for historical compatibility. So restrict the helper to only operate on Type-B connector when attempting to get the role switch from parent node. Fixes: 6fadd72943b8 ("usb: roles: get usb-role-switch from parent") Cc: stable Signed-off-by: Xu Yang Tested-by: Arnaud Ferraris Reviewed-by: Heikki Krogerus Link: https://patch.msgid.link/20260309074313.2809867-3-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman

usb: roles: set switch registered flag early on

2025-02-14T08:26:25+00:00

The role switch registration and set_role() can happen in parallel as they are invoked independent of each other. There is a possibility that a driver might spend significant amount of time in usb_role_switch_register() API due to the presence of time intensive operations like component_add() which operate under common mutex. This leads to a time window after allocating the switch and before setting the registered flag where the set role notifications are dropped. Below timeline summarizes this behavior Thread1 | Thread2 usb_role_switch_register() | | | ---> allocate switch | | | ---> component_add() | usb_role_switch_set_role() | | | | | --> Drop role notifications | | since sw->registered | | flag is not set. | | --->Set registered flag.| To avoid this, set the registered flag early on in the switch register API. Fixes: b787a3e78175 ("usb: roles: don't get/set_role() when usb_role_switch is unregistered") Cc: stable Signed-off-by: Elson Roy Serrao Reviewed-by: Heikki Krogerus Link: https://lore.kernel.org/r/20250206193950.22421-1-quic_eserrao@quicinc.com Signed-off-by: Greg Kroah-Hartman

usb: Switch back to struct platform_driver::remove()

2024-10-04T13:13:03+00:00

After commit 0edb555a65d1 ("platform: Make platform_driver::remove() return void") .remove() is (again) the right callback to implement for platform drivers. Convert all platform drivers below drivers/usb to use .remove(), with the eventual goal to drop struct platform_driver::remove_new(). As .remove() and .remove_new() have the same prototypes, conversion is done by just changing the structure member name in the driver initializer. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20240924084329.53094-2-u.kleine-koenig@baylibre.com Signed-off-by: Greg Kroah-Hartman

usb: roles: Improve the fix for a false positive recursive locking complaint

2024-09-13T05:36:02+00:00

Improve commit fc88bb116179 ("usb: roles: add lockdep class key to struct usb_role_switch") as follows: * Move the lock class key declaration just above the mutex declaration such that the declaration order of these objects matches their initialization order. * Destroy the mutex and lock class key just before these objects are freed. This makes it easier to verify that the destruction calls happen after the last use of these objects. * Instead of switching the mutex key to the dynamic lock class key after initialization of the mutex has completed, initialize the mutex with the dynamic lock class key. Cc: Amit Sunil Dhamne Cc: Badhri Jagan Sridharan Cc: Hans de Goede Cc: Andy Shevchenko Cc: Heikki Krogerus Cc: Greg Kroah-Hartman Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20240912223956.3554086-4-bvanassche@acm.org Signed-off-by: Greg Kroah-Hartman

usb: roles: add lockdep class key to struct usb_role_switch

2024-08-25T11:45:56+00:00

There can be multiple role switch devices running on a platform. Given that lockdep is not capable of differentiating between locks of different instances, false positive warnings for circular locking are reported. To prevent this, register unique lockdep key for each of the individual instances. Signed-off-by: Amit Sunil Dhamne Reviewed-by: Badhri Jagan Sridharan Link: https://lore.kernel.org/r/20240822223717.253433-1-amitsd@google.com Signed-off-by: Greg Kroah-Hartman

Merge v6.8-rc6 into usb-next

2024-02-26T05:53:50+00:00

We need it here for the USB fixes, and it resolves a merge conflict as reported in linux-next in drivers/usb/roles/class.c Reported-by: Stephen Rothwell Signed-off-by: Greg Kroah-Hartman

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

2024-02-19T08:30:41+00:00

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: fde0aa6c175a ("usb: common: Small class for USB role switches") cc: stable@vger.kernel.org Signed-off-by: Xu Yang Acked-by: Heikki Krogerus Link: https://lore.kernel.org/r/20240129093739.2371530-2-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman

usb: roles: fix NULL pointer issue when put module's reference

2024-02-19T08:30:41+00:00

In current design, usb role class driver will get usb_role_switch parent's module reference after the user get usb_role_switch device and put the reference after the user put the usb_role_switch device. However, the parent device of usb_role_switch may be removed before the user put the usb_role_switch. If so, then, NULL pointer issue will be met when the user put the parent module's reference. This will save the module pointer in structure of usb_role_switch. Then, we don't need to find module by iterating long relations. Fixes: 5c54fcac9a9d ("usb: roles: Take care of driver module reference counting") cc: stable@vger.kernel.org Signed-off-by: Xu Yang Acked-by: Heikki Krogerus Link: https://lore.kernel.org/r/20240129093739.2371530-1-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman

usb: roles: Link the switch to its connector

2024-02-17T16:02:42+00:00

This is probable useful information to have in user space in general, but it's primarily needed for the xHCI DbC (Debug Capability). When xHCI DbC is being used, the USB port needs to be muxed to the xHCI even in device role. In xHCI DbC mode, the xHCI is the USB device controller. Tested-by: Uday Bhat Signed-off-by: Heikki Krogerus Reviewed-by: Prashant Malani Link: https://lore.kernel.org/r/20240213130018.3029991-2-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman

USB: roles: make role_class a static const structure

2023-06-20T14:20:40+00:00

Now that the driver core allows for struct class to be in read-only memory, move the role_class structure to be declared at build time placing it into read-only memory, instead of having to be dynamically allocated at load time. Suggested-by: Greg Kroah-Hartman Signed-off-by: Ivan Orlov Link: https://lore.kernel.org/r/20230620094412.508580-7-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman