On Thu, 2020-07-23 at 10:35 +0000, Peter Chen wrote: > > > > > > > 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? > > > > mfi_fc_probe() isn't called because the device already has the > > generic driver > > attached by the time the apple-mfi-fastcharge driver is loaded. > > Would you please explain more, why only this driver has this issue? > Seem you > create a struct usb_device_driver, but not struct usb_driver, few > drivers do like > that. You may see drivers/usb/misc/ehset.c and > drivers/usb/misc/appledisplay.c > as an example. It's a _device_ driver, not an interface driver. It's the only driver that has the problem because it's the only non-generic device driver :)