-From ec51fbd1b8a2bca2948dede99c14ec63dc57ff6b Mon Sep 17 00:00:00 2001
-From: Bjørn Mork <bjorn@mork.no>
-Date: Fri, 6 Jan 2023 17:07:38 +0100
-Subject: [PATCH] r8152: add USB device driver for config selection
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-Subclassing the generic USB device driver to override the
-default configuration selection regardless of matching interface
-drivers.
-
-The r815x family devices expose a vendor specific function which
-the r8152 interface driver wants to handle. This is the preferred
-device mode. Additionally one or more USB class functions are
-usually supported for hosts lacking a vendor specific driver. The
-choice is USB configuration based, with one alternate function per
-configuration.
-
-Example device with both NCM and ECM alternate cfgs:
-
-T: Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 4 Spd=5000 MxCh= 0
-D: Ver= 3.20 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 9 #Cfgs= 3
-P: Vendor=0bda ProdID=8156 Rev=31.00
-S: Manufacturer=Realtek
-S: Product=USB 10/100/1G/2.5G LAN
-S: SerialNumber=001000001
-C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=256mA
-I:* If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=00 Driver=r8152
-E: Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
-E: Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
-E: Ad=83(I) Atr=03(Int.) MxPS= 2 Ivl=128ms
-C: #Ifs= 2 Cfg#= 2 Atr=a0 MxPwr=256mA
-I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=0d Prot=00 Driver=
-E: Ad=83(I) Atr=03(Int.) MxPS= 16 Ivl=128ms
-I: If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=01 Driver=
-I: If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=01 Driver=
-E: Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
-E: Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
-C: #Ifs= 2 Cfg#= 3 Atr=a0 MxPwr=256mA
-I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=06 Prot=00 Driver=
-E: Ad=83(I) Atr=03(Int.) MxPS= 16 Ivl=128ms
-I: If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=00 Driver=
-I: If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=
-E: Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
-E: Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
-
-A problem with this is that Linux will prefer class functions over
-vendor specific functions. Using the above example, Linux defaults
-to cfg #2, running the device in a sub-optimal NCM mode.
-
-Previously we've attempted to work around the problem by
-blacklisting the devices in the ECM class driver "cdc_ether", and
-matching on the ECM class function in the vendor specific interface
-driver. The latter has been used to switch back to the vendor
-specific configuration when the driver is probed for a class
-function.
-
-This workaround has several issues;
-- class driver blacklists is additional maintanence cruft in an
- unrelated driver
-- class driver blacklists prevents users from optionally running
- the devices in class mode
-- each device needs double match entries in the vendor driver
-- the initial probing as a class function slows down device
- discovery
-
-Now these issues have become even worse with the introduction of
-firmware supporting both NCM and ECM, where NCM ends up as the
-default mode in Linux. To use the same workaround, we now have
-to blacklist the devices in to two different class drivers and
-add yet another match entry to the vendor specific driver.
-
-This patch implements an alternative workaround strategy -
-independent of the interface drivers. It avoids adding a
-blacklist to the cdc_ncm driver and will let us remove the
-existing blacklist from the cdc_ether driver.
-
-As an additional bonus, removing the blacklists allow users to
-select one of the other device modes if wanted.
-
-Signed-off-by: Bjørn Mork <bjorn@mork.no>
-Signed-off-by: David S. Miller <davem@davemloft.net>
----
- drivers/net/usb/r8152.c | 113 ++++++++++++++++++++++++++++------------
- 1 file changed, 81 insertions(+), 32 deletions(-)
-
---- a/drivers/net/usb/r8152.c
-+++ b/drivers/net/usb/r8152.c
-@@ -9675,6 +9675,9 @@ static int rtl8152_probe(struct usb_inte
- if (version == RTL_VER_UNKNOWN)
- return -ENODEV;
-
-+ if (intf->cur_altsetting->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
-+ return -ENODEV;
-+
- if (!rtl_vendor_mode(intf))
- return -ENODEV;
-
-@@ -9875,43 +9878,35 @@ static void rtl8152_disconnect(struct us
- }
- }
-
--#define REALTEK_USB_DEVICE(vend, prod) { \
-- USB_DEVICE_INTERFACE_CLASS(vend, prod, USB_CLASS_VENDOR_SPEC), \
--}, \
--{ \
-- USB_DEVICE_AND_INTERFACE_INFO(vend, prod, USB_CLASS_COMM, \
-- USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE), \
--}
-
- /* table of devices that work with this driver */
- static const struct usb_device_id rtl8152_table[] = {
- /* Realtek */
-- REALTEK_USB_DEVICE(VENDOR_ID_REALTEK, 0x8050),
-- REALTEK_USB_DEVICE(VENDOR_ID_REALTEK, 0x8053),
-- REALTEK_USB_DEVICE(VENDOR_ID_REALTEK, 0x8152),
-- REALTEK_USB_DEVICE(VENDOR_ID_REALTEK, 0x8153),
-- REALTEK_USB_DEVICE(VENDOR_ID_REALTEK, 0x8155),
-- REALTEK_USB_DEVICE(VENDOR_ID_REALTEK, 0x8156),
-+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x8050) },
-+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x8053) },
-+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x8152) },
-+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x8153) },
-+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x8155) },
-+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x8156) },
-
- /* Microsoft */
-- REALTEK_USB_DEVICE(VENDOR_ID_MICROSOFT, 0x07ab),
-- REALTEK_USB_DEVICE(VENDOR_ID_MICROSOFT, 0x07c6),
-- REALTEK_USB_DEVICE(VENDOR_ID_MICROSOFT, 0x0927),
-- REALTEK_USB_DEVICE(VENDOR_ID_MICROSOFT, 0x0c5e),
-- REALTEK_USB_DEVICE(VENDOR_ID_SAMSUNG, 0xa101),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x304f),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x3054),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x3062),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x3069),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x3082),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x7205),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x720c),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x7214),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0x721e),
-- REALTEK_USB_DEVICE(VENDOR_ID_LENOVO, 0xa387),
-- REALTEK_USB_DEVICE(VENDOR_ID_LINKSYS, 0x0041),
-- REALTEK_USB_DEVICE(VENDOR_ID_NVIDIA, 0x09ff),
-- REALTEK_USB_DEVICE(VENDOR_ID_TPLINK, 0x0601),
-+ { USB_DEVICE(VENDOR_ID_MICROSOFT, 0x07ab) },
-+ { USB_DEVICE(VENDOR_ID_MICROSOFT, 0x07c6) },
-+ { USB_DEVICE(VENDOR_ID_MICROSOFT, 0x0927) },
-+ { USB_DEVICE(VENDOR_ID_SAMSUNG, 0xa101) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x304f) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x3054) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x3062) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x3069) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x3082) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x7205) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x720c) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x7214) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0x721e) },
-+ { USB_DEVICE(VENDOR_ID_LENOVO, 0xa387) },
-+ { USB_DEVICE(VENDOR_ID_LINKSYS, 0x0041) },
-+ { USB_DEVICE(VENDOR_ID_NVIDIA, 0x09ff) },
-+ { USB_DEVICE(VENDOR_ID_TPLINK, 0x0601) },
- {}
- };
-
-@@ -9931,7 +9926,61 @@ static struct usb_driver rtl8152_driver
- .disable_hub_initiated_lpm = 1,
- };
-
--module_usb_driver(rtl8152_driver);
-+static int rtl8152_cfgselector_probe(struct usb_device *udev)
-+{
-+ struct usb_host_config *c;
-+ int i, num_configs;
-+
-+ /* The vendor mode is not always config #1, so to find it out. */
-+ c = udev->config;
-+ num_configs = udev->descriptor.bNumConfigurations;
-+ for (i = 0; i < num_configs; (i++, c++)) {
-+ struct usb_interface_descriptor *desc = NULL;
-+
-+ if (!c->desc.bNumInterfaces)
-+ continue;
-+ desc = &c->intf_cache[0]->altsetting->desc;
-+ if (desc->bInterfaceClass == USB_CLASS_VENDOR_SPEC)
-+ break;
-+ }
-+
-+ 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;
-+}
-+
-+static struct usb_device_driver rtl8152_cfgselector_driver = {
-+ .name = MODULENAME "-cfgselector",
-+ .probe = rtl8152_cfgselector_probe,
-+ .id_table = rtl8152_table,
-+ .generic_subclass = 1,
-+};
-+
-+static int __init rtl8152_driver_init(void)
-+{
-+ int ret;
-+
-+ ret = usb_register_device_driver(&rtl8152_cfgselector_driver, THIS_MODULE);
-+ if (ret)
-+ return ret;
-+ return usb_register(&rtl8152_driver);
-+}
-+
-+static void __exit rtl8152_driver_exit(void)
-+{
-+ usb_deregister(&rtl8152_driver);
-+ usb_deregister_device_driver(&rtl8152_cfgselector_driver);
-+}
-+
-+module_init(rtl8152_driver_init);
-+module_exit(rtl8152_driver_exit);
-
- MODULE_AUTHOR(DRIVER_AUTHOR);
- MODULE_DESCRIPTION(DRIVER_DESC);