[PATCH net 2/2] r8152: Switch to using choose_configuration

From: Maxim Mikityanskiy <maxtram95@gmail.com>
To: "David S. Miller" <davem@davemloft.net>,
	"Bjørn Mork" <bjorn@mork.no>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Hayes Wang" <hayeswang@realtek.com>
Cc: Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Douglas Anderson <dianders@chromium.org>,
	Grant Grundler <grundler@chromium.org>,
	linux-usb@vger.kernel.org, netdev@vger.kernel.org,
	Maxim Mikityanskiy <maxtram95@gmail.com>
Subject: [PATCH net 2/2] r8152: Switch to using choose_configuration
Date: Sun, 24 Dec 2023 01:35:23 +0200	[thread overview]
Message-ID: <20231223233523.4411-3-maxtram95@gmail.com> (raw)
In-Reply-To: <20231223233523.4411-1-maxtram95@gmail.com>

With the introduction of r8152-cfgselector, the following regression
appeared on machines that use usbguard: the netdev appears only when the
USB device is inserted the first time (before the module is loaded), but
on the second and next insertions no netdev is registered.

It happens because the device is probed as unauthorized, and usbguard
gives it an authorization a moment later. If the module is not loaded,
it's normally loaded slower than the authorization is given, and
everything works. If the module is already loaded, the cfgselector's
probe function runs first, but then usb_authorize_device kicks in and
changes the configuration to something chosen by the standard
usb_choose_configuration. rtl8152_probe refuses to probe non-vendor
configurations, and the user ends up without a netdev.

The previous commit added possibility to override
usb_choose_configuration. Use it to fix the bug and pick the right
configuration on both probe and authorization.

Fixes: ec51fbd1b8a2 ("r8152: add USB device driver for config selection")
Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>
---
 drivers/net/usb/r8152.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 9bf2140fd0a1..f0ac31a94f3c 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -10070,6 +10070,11 @@ static struct usb_driver rtl8152_driver = {
 };
 
 static int rtl8152_cfgselector_probe(struct usb_device *udev)
+{
+	return 0;
+}
+
+static int rtl8152_cfgselector_choose_configuration(struct usb_device *udev)
 {
 	struct usb_host_config *c;
 	int i, num_configs;
@@ -10078,7 +10083,7 @@ static int rtl8152_cfgselector_probe(struct usb_device *udev)
 	 * driver supports it.
 	 */
 	if (__rtl_get_hw_ver(udev) == RTL_VER_UNKNOWN)
-		return 0;
+		return -EOPNOTSUPP;
 
 	/* The vendor mode is not always config #1, so to find it out. */
 	c = udev->config;
@@ -10094,20 +10099,15 @@ 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 -EOPNOTSUPP;
 
-	return 0;
+	return c->desc.bConfigurationValue;
 }
 
 static struct usb_device_driver rtl8152_cfgselector_driver = {
 	.name =		MODULENAME "-cfgselector",
 	.probe =	rtl8152_cfgselector_probe,
+	.choose_configuration = rtl8152_cfgselector_choose_configuration,
 	.id_table =	rtl8152_table,
 	.generic_subclass = 1,
 	.supports_autosuspend = 1,
-- 
2.43.0

