From 77419aa403ca1395f66e1e3de87743f54ba144b6 Mon Sep 17 00:00:00 2001 From: Bastien Nocera Date: Wed, 16 Oct 2019 11:39:32 +0200 Subject: [PATCH] USB: Fallback to generic driver when specific driver fails If ->probe fails for a device specific driver, ask the driver core to reprobe us, after having flagged the device for the generic driver to be forced. Signed-off-by: Bastien Nocera Acked-by: Alan Stern Link: https://lore.kernel.org/r/20191016093933.693-6-hadess@hadess.net Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 5 ++++- drivers/usb/core/generic.c | 3 +++ include/linux/usb.h | 1 + 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 9d1502a..f81606c 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -270,7 +270,10 @@ static int usb_probe_device(struct device *dev) return error; error = udriver->probe(udev); - /* TODO: fallback to generic driver in case of error */ + if (error == -ENODEV && udriver != &usb_generic_driver) { + udev->use_generic_driver = 1; + return -EPROBE_DEFER; + } return error; } diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c index 84da85c..4626227 100644 --- a/drivers/usb/core/generic.c +++ b/drivers/usb/core/generic.c @@ -213,6 +213,9 @@ static int __check_usb_generic(struct device_driver *drv, void *data) static bool usb_generic_driver_match(struct usb_device *udev) { + if (udev->use_generic_driver) + return true; + /* * If any other driver wants the device, leave the device to this other * driver. diff --git a/include/linux/usb.h b/include/linux/usb.h index 3663bd7..ca1a5f1 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -708,6 +708,7 @@ struct usb_device { unsigned lpm_disable_count; u16 hub_delay; + unsigned use_generic_driver:1; }; #define to_usb_device(d) container_of(d, struct usb_device, dev) -- 2.7.4