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USB: Fix device driver race

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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: 88b7381a93 ("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>
This commit is contained in:
Bastien Nocera 2020-08-18 13:04:45 +02:00 • committed by Greg Kroah-Hartman
parent adb6e6ac20
commit d5643d2249
1 changed files with 38 additions and 2 deletions
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40
drivers/usb/core/driver.c
View file

@ -905,6 +905,35 @@ static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
return 0; 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 * usb_register_device_driver - register a USB device (not interface) driver
* @new_udriver: USB operations for the device driver * @new_udriver: USB operations for the device driver
@ -934,13 +963,20 @@ int usb_register_device_driver(struct usb_device_driver *new_udriver,
retval = driver_register(&new_udriver->drvwrap.driver); retval = driver_register(&new_udriver->drvwrap.driver);
if (!retval) if (!retval) {
pr_info("%s: registered new device driver %s\n", pr_info("%s: registered new device driver %s\n",
usbcore_name, new_udriver->name); 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 " printk(KERN_ERR "%s: error %d registering device "
" driver %s\n", " driver %s\n",
usbcore_name, retval, new_udriver->name); usbcore_name, retval, new_udriver->name);
}
return retval; return retval;
} }