On 20-07-22 17:53:25, Bastien Nocera wrote: > On Wed, 2020-07-22 at 11:26 -0400, Alan Stern wrote: > > On Wed, Jul 22, 2020 at 11:46:27AM +0200, 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. > > > > > > Signed-off-by: Bastien Nocera <hadess@xxxxxxxxxx> > > > --- > > > drivers/usb/core/driver.c | 31 +++++++++++++++++++++++++++++-- > > > 1 file changed, 29 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c > > > index f81606c6a35b..a6187dd2186c 100644 > > > --- a/drivers/usb/core/driver.c > > > +++ b/drivers/usb/core/driver.c > > > @@ -905,6 +905,30 @@ static int usb_uevent(struct device *dev, > > > struct kobj_uevent_env *env) > > > return 0; > > > } > > > > > > +static int __usb_bus_reprobe_drivers(struct device *dev, void > > > *data) > > > +{ > > > + struct usb_device_driver *udriver = to_usb_device_driver(dev- > > > >driver); > > > + struct usb_device *udev = to_usb_device(dev); > > > + > > > + if (udriver == &usb_generic_driver && > > > + !udev->use_generic_driver) > > > + return device_reprobe(dev); > > > + > > > + return 0; > > > +} > > > + > > > +static int __usb_device_driver_added(struct device_driver *drv, > > > void *data) > > > +{ > > > + struct usb_device_driver *udrv = to_usb_device_driver(drv); > > > + > > > + if (udrv->match) { > > > + bus_for_each_dev(&usb_bus_type, NULL, udrv, > > > + __usb_bus_reprobe_drivers); > > > > What does udrv get used for here? > > > > > + } > > > + > > > + return 0; > > > +} > > > + > > > /** > > > * usb_register_device_driver - register a USB device (not > > > interface) driver > > > * @new_udriver: USB operations for the device driver > > > @@ -934,13 +958,16 @@ int usb_register_device_driver(struct > > > usb_device_driver *new_udriver, > > > > > > retval = driver_register(&new_udriver->drvwrap.driver); > > > > > > - if (!retval) > > > + if (!retval) { > > > + bus_for_each_drv(&usb_bus_type, NULL, NULL, > > > + __usb_device_driver_added); > > > > This looks funny. You're calling both bus_for_each_drv() and > > bus_for_each_dev(). Can't you skip this iterator and just call > > bus_for_each_dev() directly? > > You're right, looks like this could be simplified somewhat. I'm > building and testing a smaller patch. > What do you mean "reprobe" for your device? Do you mean the mfi_fc_probe is not called? If it is, Would you please check why usb_device_match at drivers/usb/core/driver.c does not return true for your device? -- Thanks, Peter Chen