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authorDouglas Anderson <dianders@chromium.org>2023-12-01 10:29:51 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-12-04 22:28:20 +0900
commita87b8e3be926af0fc3b9b1af42b1127bd1ff077c (patch)
tree890d87f9e19fd1a2b37a7c080938b997c76c422c /drivers/usb/core
parentc2d95fcff0f01fa00d9683dddeeea6732b74c779 (diff)
usb: core: Allow subclassed USB drivers to override usb_choose_configuration()
For some USB devices we might want to do something different for usb_choose_configuration(). One example here is the r8152 driver where we want to end up using the vendor driver with the preferred interface. The r8152 driver tried to make things work by implementing a USB generic_subclass driver and then overriding the normal config selection after it happened. This is less than ideal and also caused breakage if someone deauthorized and re-authorized the USB device because the USB core ended up going back to it's default logic for choosing the best config. I made an attempt to fix this [1] but it was a bit ugly. Let's do this better and allow USB generic_subclass drivers to override usb_choose_configuration(). [1] https://lore.kernel.org/r/20231130154337.1.Ie00e07f07f87149c9ce0b27ae4e26991d307e14b@changeid Suggested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20231201102946.v2.2.Iade5fa31997f1a0ca3e1dec0591633b02471df12@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/generic.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index 740342a2812a..dcb897158228 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -59,10 +59,17 @@ int usb_choose_configuration(struct usb_device *udev)
int num_configs;
int insufficient_power = 0;
struct usb_host_config *c, *best;
+ struct usb_device_driver *udriver = to_usb_device_driver(udev->dev.driver);
if (usb_device_is_owned(udev))
return 0;
+ if (udriver->choose_configuration) {
+ i = udriver->choose_configuration(udev);
+ if (i >= 0)
+ return i;
+ }
+
best = NULL;
c = udev->config;
num_configs = udev->descriptor.bNumConfigurations;