r8152: Choose our USB config with choose_configuration() rather than probe()

If you deauthorize the r8152 device (by writing 0 to the "authorized"
field in sysfs) and then reauthorize it (by writing a 1) then it no
longer works. This is because when you do the above we lose the
special configuration that we set in rtl8152_cfgselector_probe().
Deauthorizing causes the config to be set to -1 and then reauthorizing
runs the default logic for choosing the best config.

I made an attempt to fix it so that the config is kept across
deauthorizing / reauthorizing [1] but it was a bit ugly.

Let's instead use the new USB core feature to override
choose_configuration().

This patch relies upon the patches ("usb: core: Don't force USB
generic_subclass drivers to define probe()") and ("usb: core: Allow
subclassed USB drivers to override usb_choose_configuration()")

[1] https://lore.kernel.org/r/20231130154337.1.Ie00e07f07f87149c9ce0b27ae4e26991d307e14b@changeid

Fixes: ec51fbd1b8a2 ("r8152: add USB device driver for config selection")
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Grant Grundler <grundler@chromium.org>
Link: https://lore.kernel.org/r/20231201102946.v2.3.Ie00e07f07f87149c9ce0b27ae4e26991d307e14b@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 2c5c1e91ded613b5e9a23d5c5b93f70bac57c862..0da723d1132660075209abb7967425c065626558 100644 (file)
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -10053,7 +10053,7 @@ static struct usb_driver rtl8152_driver = {
        .disable_hub_initiated_lpm = 1,
 };
 
-static int rtl8152_cfgselector_probe(struct usb_device *udev)
+static int rtl8152_cfgselector_choose_configuration(struct usb_device *udev)
 {
        struct usb_host_config *c;
        int i, num_configs;
@@ -10080,19 +10080,13 @@ static int rtl8152_cfgselector_probe(struct usb_device *udev)
        if (i == num_configs)
                return -ENODEV;
 
-       if (usb_set_configuration(udev, c->desc.bConfigurationValue)) {
-               dev_err(&udev->dev, "Failed to set configuration %d\n",
-                       c->desc.bConfigurationValue);
-               return -ENODEV;
-       }
-
-       return 0;
+       return c->desc.bConfigurationValue;
 }
 
 static struct usb_device_driver rtl8152_cfgselector_driver = {
-       .name =         MODULENAME "-cfgselector",
-       .probe =        rtl8152_cfgselector_probe,
-       .id_table =     rtl8152_table,
+       .name = MODULENAME "-cfgselector",
+       .choose_configuration = rtl8152_cfgselector_choose_configuration,
+       .id_table = rtl8152_table,
        .generic_subclass = 1,
        .supports_autosuspend = 1,
 };