kernel/linux.git/drivers/usb/roles/class.c, branch v5.15.208

usb: roles: set switch registered flag early on

2025-03-13T11:50:37+00:00

commit 634775a752a86784511018a108f3b530cc3399a7 upstream. 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: roles: don't get/set_role() when usb_role_switch is unregistered

2024-03-01T12:21:50+00:00

commit b787a3e781759026a6212736ef8e52cf83d1821a 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: 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

2024-03-01T12:21:50+00:00

commit 1c9be13846c0b2abc2480602f8ef421360e1ad9e upstream. 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: fix of node refcount leak in usb_role_switch_is_parent()

2022-12-31T12:14:30+00:00

[ Upstream commit 1ab30c610630da5391a373cddb8a065bf4c4bc01 ] I got the following report while doing device(mt6370-tcpc) load test with CONFIG_OF_UNITTEST and CONFIG_OF_DYNAMIC enabled: OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /i2c/pmic@34 The 'parent' returned by fwnode_get_parent() with refcount incremented. it needs be put after using. Fixes: 6fadd72943b8 ("usb: roles: get usb-role-switch from parent") Reviewed-by: Heikki Krogerus Signed-off-by: Yang Yingliang Link: https://lore.kernel.org/r/20221122111226.251588-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: roles: add helper usb_role_string()

2021-05-27T07:17:18+00:00

Introduces usb_role_string() function, which returns a human-readable name of provided usb role, it's useful to make the log readable. Reviewed-by: Heikki Krogerus Signed-off-by: Chunfeng Yun Link: https://lore.kernel.org/r/1621932786-9335-1-git-send-email-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman

usb: roles: Call try_module_get() from usb_role_switch_find_by_fwnode()

2021-04-09T14:07:03+00:00

usb_role_switch_find_by_fwnode() returns a reference to the role-switch which must be put by calling usb_role_switch_put(). usb_role_switch_put() calls module_put(sw->dev.parent->driver->owner), add a matching try_module_get() to usb_role_switch_find_by_fwnode(), making it behave the same as the other usb_role_switch functions which return a reference. This avoids a WARN_ON being hit at kernel/module.c:1158 due to the module-refcount going below 0. Fixes: c6919d5e0cd1 ("usb: roles: Add usb_role_switch_find_by_fwnode()") Cc: stable Reviewed-by: Guenter Roeck Reviewed-by: Heikki Krogerus Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20210409124136.65591-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman

device connection: Remove struct device_connection

2020-09-07T09:14:09+00:00

Since the connection descriptors can't be stored into the list anymore, there is no need for the data structure. Signed-off-by: Heikki Krogerus Link: https://lore.kernel.org/r/20200904125123.83725-4-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: roles: Switch on role-switch uevent reporting

2020-05-13T12:20:49+00:00

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 Cc: Greg Kroah-Hartman Cc: Chunfeng Yun Cc: Suzuki K Poulose Cc: Alexandre Belloni Cc: Wen Yang Cc: chenqiwu Cc: linux-kernel@vger.kernel.org Signed-off-by: Bryan O'Donoghue Link: https://lore.kernel.org/r/20200508162937.2566818-1-bryan.odonoghue@linaro.org Signed-off-by: Greg Kroah-Hartman

usb: roles: Allow the role switches to be named

2020-03-04T10:12:50+00:00

The switch devices have been named by using the name of the parent device as base for now, but if for example the parent device controls multiple muxes, that will not work. Adding an optional member "name" to the switch descriptor that can be used for naming the switch during registration. Signed-off-by: Heikki Krogerus Link: https://lore.kernel.org/r/20200302135353.56659-7-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: roles: Provide the switch drivers handle to the switch in the API

2020-03-04T10:12:50+00:00

The USB role callback functions had a parameter pointing to the parent device (struct device) of the switch. The assumption was that the switch parent is always the controller. Firstly, that may not be true in every case, and secondly, it prevents us from supporting devices that supply multiple muxes. Changing the first parameter of usb_role_switch_set_t and usb_role_switch_get_t from struct device to struct usb_role_switch. Cc: Peter Chen Cc: Felipe Balbi Cc: Chunfeng Yun Cc: Bin Liu Signed-off-by: Heikki Krogerus Link: https://lore.kernel.org/r/20200302135353.56659-6-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman