* [PATCH v2 5/6] USB: Fallback to generic driver when specific driver fails
@ 2019-10-15 14:28 Bastien Nocera
0 siblings, 0 replies; 2+ messages in thread
From: Bastien Nocera @ 2019-10-15 14:28 UTC (permalink / raw)
To: Alan Stern, linux-usb, Greg Kroah-Hartman, Benjamin Tissoires
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>
---
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 e86065f3be7f..6190986c7d99 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 a3f0142b816a..669579b37e54 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)
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH v2 5/6] USB: Fallback to generic driver when specific driver fails
2019-10-15 14:31 [PATCH v2 0/6] Add Apple MFi fastcharge USB device driver Bastien Nocera
@ 2019-10-15 14:31 ` Bastien Nocera
0 siblings, 0 replies; 2+ messages in thread
From: Bastien Nocera @ 2019-10-15 14:31 UTC (permalink / raw)
To: linux-usb; +Cc: Greg Kroah-Hartman, Benjamin Tissoires, Bastien Nocera
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>
---
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 e86065f3be7f..6190986c7d99 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 a3f0142b816a..669579b37e54 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)
--
2.21.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2019-10-15 14:31 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-15 14:28 [PATCH v2 5/6] USB: Fallback to generic driver when specific driver fails Bastien Nocera
2019-10-15 14:31 [PATCH v2 0/6] Add Apple MFi fastcharge USB device driver Bastien Nocera
2019-10-15 14:31 ` [PATCH v2 5/6] USB: Fallback to generic driver when specific driver fails Bastien Nocera
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).