From: Bastien Nocera hadess@hadess.net
commit d5643d2249b279077427b2c2b2ffae9b70c95b0b upstream.
When a new device with a specialised device driver is plugged in, the new driver will be modprobe()'d but the driver core will attach the "generic" driver to the device.
After that, nothing will trigger a reprobe when the modprobe()'d device driver has finished initialising, as the device has the "generic" driver attached to it.
Trigger a reprobe ourselves when new specialised drivers get registered.
Fixes: 88b7381a939d ("USB: Select better matching USB drivers when available") Signed-off-by: Bastien Nocera hadess@hadess.net Cc: stable stable@vger.kernel.org Acked-by: Alan Stern stern@rowland.harvard.edu Link: https://lore.kernel.org/r/20200818110445.509668-3-hadess@hadess.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/core/driver.c | 40 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 38 insertions(+), 2 deletions(-)
--- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -905,6 +905,35 @@ static int usb_uevent(struct device *dev return 0; }
+static bool is_dev_usb_generic_driver(struct device *dev) +{ + struct usb_device_driver *udd = dev->driver ? + to_usb_device_driver(dev->driver) : NULL; + + return udd == &usb_generic_driver; +} + +static int __usb_bus_reprobe_drivers(struct device *dev, void *data) +{ + struct usb_device_driver *new_udriver = data; + struct usb_device *udev; + int ret; + + if (!is_dev_usb_generic_driver(dev)) + return 0; + + udev = to_usb_device(dev); + if (usb_device_match_id(udev, new_udriver->id_table) == NULL && + (!new_udriver->match || new_udriver->match(udev) != 0)) + return 0; + + ret = device_reprobe(dev); + if (ret && ret != -EPROBE_DEFER) + dev_err(dev, "Failed to reprobe device (error %d)\n", ret); + + return 0; +} + /** * usb_register_device_driver - register a USB device (not interface) driver * @new_udriver: USB operations for the device driver @@ -934,13 +963,20 @@ int usb_register_device_driver(struct us
retval = driver_register(&new_udriver->drvwrap.driver);
- if (!retval) + if (!retval) { pr_info("%s: registered new device driver %s\n", usbcore_name, new_udriver->name); - else + /* + * Check whether any device could be better served with + * this new driver + */ + bus_for_each_dev(&usb_bus_type, NULL, new_udriver, + __usb_bus_reprobe_drivers); + } else { printk(KERN_ERR "%s: error %d registering device " " driver %s\n", usbcore_name, retval, new_udriver->name); + }
return retval; }