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authorBastien Nocera <hadess@hadess.net>2019-10-16 11:39:32 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-02-12 11:01:55 -0800
commit77419aa403ca1395f66e1e3de87743f54ba144b6 (patch)
tree13b24674cf8e8151b59015ec90f003d696abafad
parent88b7381a939de0fa1f1b1629c56b03dca7077309 (diff)
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 <hadess@hadess.net> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20191016093933.693-6-hadess@hadess.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/core/driver.c5
-rw-r--r--drivers/usb/core/generic.c3
-rw-r--r--include/linux/usb.h1
3 files changed, 8 insertions, 1 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 9d1502a9571d..f81606c6a35b 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 84da85c13825..4626227a6dd2 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 3663bd7b1fa4..ca1a5f1e1c5e 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)