diff mbox series

[net,v2,3/3] r8152: Choose our USB config with choose_configuration() rather than probe()

Message ID 20231201102946.v2.3.Ie00e07f07f87149c9ce0b27ae4e26991d307e14b@changeid
State New
Headers
Series net: usb: r8152: Fix lost config across deauthorize+authorize |

Commit Message

Doug Anderson Dec. 1, 2023, 6:29 p.m. UTC 
  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>
---

Changes in v2:
- ("Choose our USB config with choose_configuration()...) new for v2.

 drivers/net/usb/r8152.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

Comments

Grant Grundler Dec. 2, 2023, 6:28 a.m. UTC | #1 
On Fri, Dec 1, 2023 at 10:31 AM Douglas Anderson <dianders@chromium.org> wrote:
>
> 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>

> ---
>
> Changes in v2:
> - ("Choose our USB config with choose_configuration()...) new for v2.
>
>  drivers/net/usb/r8152.c | 16 +++++-----------
>  1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> index 2c5c1e91ded6..0da723d11326 100644
> --- 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,
>  };
> --
> 2.43.0.rc2.451.g8631bc7472-goog
>
Jakub Kicinski Dec. 5, 2023, 2:27 a.m. UTC | #2 
On Fri,  1 Dec 2023 10:29:52 -0800 Douglas Anderson wrote:
> 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()")

Acked-by: Jakub Kicinski <kuba@kernel.org>
diff mbox series

Patch

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 2c5c1e91ded6..0da723d11326 100644
--- 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,
 };