Re: [PATCH v8 3/3] USB: Fix device driver race

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Aug 18, 2020 at 08:06:20PM +0300, Sergei Shtylyov wrote:
> On 8/18/20 2:04 PM, Bastien Nocera wrote:
> 
> > 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>
> [...]
> >  drivers/usb/core/driver.c | 40 +++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 38 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
> > index f81606c6a35b..7e73e989645b 100644
> > --- a/drivers/usb/core/driver.c
> > +++ b/drivers/usb/core/driver.c
> [...]
> > @@ -934,13 +963,20 @@ int usb_register_device_driver(struct usb_device_driver *new_udriver,
> >  
> >  	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",
> 
>    Unrelated but... hm, this string literal seems weird. GregKH, would it be OK if we fix it?

Please do.