[PATCH net v6 0/3] ax88179 driver optimization

[PATCH net v6 0/3] ax88179 driver optimization

[yicongsrfy]

From: Yi Cong <yicong@kylinos.cn>

This series of patches first fixes the issues related to the vendor
driver, then reverts the previous changes to allow the vendor-specific
driver to be loaded.

Yi Cong (3):
  net: usb: support quirks in cdc_ncm
  net: usb: ax88179_178a: add USB device driver for config selection
  Revert "net: usb: ax88179_178a: Bind only to vendor-specific
    interface"

 drivers/net/usb/ax88179_178a.c | 84 ++++++++++++++++++++++++++++------
 drivers/net/usb/cdc_ncm.c      | 44 +++++++++++++++++-
 2 files changed, 112 insertions(+), 16 deletions(-)

Changes since v5:
Only change "net: usb: ax88179_178a: add USB device driver for config selection":
1. modify the registration order.
2. fix error return value.
3. delete unuse check in probe.
--
2.25.1

[PATCH net v6 1/3] net: usb: support quirks in cdc_ncm

[yicongsrfy]

From: Yi Cong <yicong@kylinos.cn>

Some vendors' USB network interface controllers (NICs) may be compatible
with multiple drivers.

I consulted with relevant vendors. Taking the AX88179 chip as an example,
NICs based on this chip may be used across various OS—for instance,
cdc_ncm is used on macOS, while ax88179_178a.ko is the intended driver
on Linux (despite a previous patch having disabled it).
Therefore, the firmware must support multiple protocols.

Currently, both cdc_ncm and ax88179_178a coexist in the Linux kernel.
Supporting both drivers simultaneously leads to the following issues:

1. Inconsistent driver loading order during reboot stress testing:
   The order in which drivers are loaded can vary across reboots,
   potentially resulting in the unintended driver being loaded. For
   example:
[    4.239893] cdc_ncm 2-1:2.0: MAC-Address: c8:a3:62:ef:99:8e
[    4.239897] cdc_ncm 2-1:2.0: setting rx_max = 16384
[    4.240149] cdc_ncm 2-1:2.0: setting tx_max = 16384
[    4.240583] cdc_ncm 2-1:2.0 usb0: register 'cdc_ncm' at usb-
xxxxx:00-1, CDC NCM, c8:a3:62:ef:99:8e
[    4.240627] usbcore: registered new interface driver cdc_ncm
[    4.240908] usbcore: registered new interface driver ax88179_178a

In this case, network connectivity functions, but the cdc_ncm driver is
loaded instead of the expected ax88179_178a.

2. Similar issues during cable plug/unplug testing:
   The same race condition can occur when reconnecting the USB device:
[   79.879922] usb 4-1: new SuperSpeed USB device number 3 using xhci_hcd
[   79.905168] usb 4-1: New USB device found, idVendor=0b95, idProduct=
1790, bcdDevice= 2.00
[   79.905185] usb 4-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[   79.905191] usb 4-1: Product: AX88179B
[   79.905198] usb 4-1: Manufacturer: ASIX
[   79.905201] usb 4-1: SerialNumber: 00EF998E
[   79.915215] ax88179_probe, bConfigurationValue:2
[   79.952638] cdc_ncm 4-1:2.0: MAC-Address: c8:a3:62:ef:99:8e
[   79.952654] cdc_ncm 4-1:2.0: setting rx_max = 16384
[   79.952919] cdc_ncm 4-1:2.0: setting tx_max = 16384
[   79.953598] cdc_ncm 4-1:2.0 eth0: register 'cdc_ncm' at usb-0000:04:
00.2-1, CDC NCM (NO ZLP), c8:a3:62:ef:99:8e
[   79.954029] cdc_ncm 4-1:2.0 eth0: unregister 'cdc_ncm' usb-0000:04:
00.2-1, CDC NCM (NO ZLP)

At this point, the network becomes unusable.

To resolve these issues, introduce a *quirks* mechanism into the usbnet
module. By adding chip-specific identification within the generic usbnet
framework, we can skip the usbnet probe process for devices that require a
dedicated driver.

Signed-off-by: Yi Cong <yicong@kylinos.cn>

---
v2: Correct the description of usbnet_quirks.h and modify the code style
v3: Add checking whether the CONFIG_USB_NET_AX88179_178A is enabled
v4: Move quirks from usbnet.ko to cdc_ncm.ko
v5: Move the ignored product information to cdc_ncm.c and delete the
    unlikely call in the if judgement
---
 drivers/net/usb/cdc_ncm.c | 44 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 5d123df0a866..7b68706b8a8a 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -2114,10 +2114,52 @@ static const struct usb_device_id cdc_devs[] = {
 };
 MODULE_DEVICE_TABLE(usb, cdc_devs);
 
+/* cdc_ncm_ignore_list:
+ * Chip info which already support int vendor specific driver,
+ * and then should be ignored in generic cdc_ncm
+ */
+static const struct usb_device_id cdc_ncm_ignore_list[] = {
+#if IS_ENABLED(CONFIG_USB_NET_AX88179_178A)
+	/* Chips already support in ax88179_178a.c */
+	{ USB_DEVICE(0x0b95, 0x1790) },
+	{ USB_DEVICE(0x0b95, 0x178a) },
+	{ USB_DEVICE(0x04b4, 0x3610) },
+	{ USB_DEVICE(0x2001, 0x4a00) },
+	{ USB_DEVICE(0x0df6, 0x0072) },
+	{ USB_DEVICE(0x04e8, 0xa100) },
+	{ USB_DEVICE(0x17ef, 0x304b) },
+	{ USB_DEVICE(0x050d, 0x0128) },
+	{ USB_DEVICE(0x0930, 0x0a13) },
+	{ USB_DEVICE(0x0711, 0x0179) },
+	{ USB_DEVICE(0x07c9, 0x000e) },
+	{ USB_DEVICE(0x07c9, 0x000f) },
+	{ USB_DEVICE(0x07c9, 0x0010) },
+	/* End of support in ax88179_178a.c */
+#endif
+
+	{ } /*END*/
+};
+
+static inline bool cdc_ncm_ignore(struct usb_interface *intf)
+{
+	return !!usb_match_id(intf, cdc_ncm_ignore_list);
+}
+
+static int cdc_ncm_probe(struct usb_interface *intf, const struct usb_device_id *prod)
+{
+	/* Should it be ignored? */
+	if (cdc_ncm_ignore(intf)) {
+		dev_dbg(&intf->dev, "cdc_ncm ignore this device!\n");
+		return -ENODEV;
+	}
+
+	return usbnet_probe(intf, prod);
+}
+
 static struct usb_driver cdc_ncm_driver = {
 	.name = "cdc_ncm",
 	.id_table = cdc_devs,
-	.probe = usbnet_probe,
+	.probe = cdc_ncm_probe,
 	.disconnect = usbnet_disconnect,
 	.suspend = usbnet_suspend,
 	.resume = usbnet_resume,
-- 
2.25.1

[PATCH net v6 2/3] net: usb: ax88179_178a: add USB device driver for config selection

[yicongsrfy]

From: Yi Cong <yicong@kylinos.cn>

A similar reason was raised in commit ec51fbd1b8a2 ("r8152: add USB
device driver for config selection"):
Linux prioritizes probing non-vendor-specific configurations.

Referring to the implementation of this patch, cfgselect is also
used for ax88179 to override the default configuration selection.

Signed-off-by: Yi Cong <yicong@kylinos.cn>
Suggested-by: Michal Pecio <michal.pecio@gmail.com>
Link: https://lore.kernel.org/all/20251011075314.572741-1-yicongsrfy@163.com/
Link: https://lore.kernel.org/all/20250928014631.2832243-1-yicongsrfy@163.com/

---
v2: fix warning from checkpatch.
v5: 1. use KBUILD_MODNAME to obtain the module name.
    2. add error handling when usb_register fail.
    3. use .choose_configuration instead of .probe.
    4. reorder deregister logic.
v6: 1. modify the registration order.
    2. fix error return value.
    3. delete unuse check in probe.
---
 drivers/net/usb/ax88179_178a.c | 58 ++++++++++++++++++++++++++++++++--
 1 file changed, 56 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index b034ef8a73ea..bad306a68644 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1941,7 +1941,7 @@ static const struct usb_device_id products[] = {
 MODULE_DEVICE_TABLE(usb, products);
 
 static struct usb_driver ax88179_178a_driver = {
-	.name =		"ax88179_178a",
+	.name =		KBUILD_MODNAME,
 	.id_table =	products,
 	.probe =	usbnet_probe,
 	.suspend =	ax88179_suspend,
@@ -1952,7 +1952,61 @@ static struct usb_driver ax88179_178a_driver = {
 	.disable_hub_initiated_lpm = 1,
 };
 
-module_usb_driver(ax88179_178a_driver);
+static int ax88179_cfgselector_choose_configuration(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;
+
+	return c->desc.bConfigurationValue;
+}
+
+static struct usb_device_driver ax88179_cfgselector_driver = {
+	.name =	KBUILD_MODNAME "-cfgselector",
+	.choose_configuration =	ax88179_cfgselector_choose_configuration,
+	.id_table = products,
+	.generic_subclass = 1,
+	.supports_autosuspend = 1,
+};
+
+static int __init ax88179_driver_init(void)
+{
+	int ret;
+
+	ret = usb_register(&ax88179_178a_driver);
+	if (ret)
+		return ret;
+
+	ret = usb_register_device_driver(&ax88179_cfgselector_driver, THIS_MODULE);
+	if (ret)
+		usb_deregister(&ax88179_178a_driver);
+
+	return ret;
+}
+
+static void __exit ax88179_driver_exit(void)
+{
+	usb_deregister_device_driver(&ax88179_cfgselector_driver);
+	usb_deregister(&ax88179_178a_driver);
+}
+
+module_init(ax88179_driver_init);
+module_exit(ax88179_driver_exit);
 
 MODULE_DESCRIPTION("ASIX AX88179/178A based USB 3.0/2.0 Gigabit Ethernet Devices");
 MODULE_LICENSE("GPL");
-- 
2.25.1

[PATCH net v6 3/3] Revert "net: usb: ax88179_178a: Bind only to vendor-specific interface"

[yicongsrfy]

From: Yi Cong <yicong@kylinos.cn>

This reverts commit c67cc4315a8e605ec875bd3a1210a549e3562ddc.

Currently, in the Linux kernel, USB NIC with ASIX chips use the cdc_ncm
driver. However, this driver lacks functionality and performs worse than
the vendor's proprietary driver. In my testing, I have identified the
following issues:

1. The cdc_ncm driver does not support changing the link speed via
   ethtool because the corresponding callback function is set to NULL.
2. The CDC protocol does not support retrieving the network duplex status.
3. In TCP_RR and UDP_RR tests, the performance of the cdc_ncm driver
   is significantly lower than that of the vendor's driver:
Average of three netperf runs: `netperf -t {TCP/UDP_RR} -H serverIP -l 120`
- cdc_ncm.ko: TCP_RR: 740, UDP_RR: 750
- ax88179_178a.ko: TCP_RR: 8900, UDP_RR: 9200

Signed-off-by: Yi Cong <yicong@kylinos.cn>
---
 drivers/net/usb/ax88179_178a.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index bad306a68644..f6264cfbab06 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1885,55 +1885,55 @@ static const struct driver_info at_umc2000sp_info = {
 static const struct usb_device_id products[] = {
 {
 	/* ASIX AX88179 10/100/1000 */
-	USB_DEVICE_AND_INTERFACE_INFO(0x0b95, 0x1790, 0xff, 0xff, 0),
+	USB_DEVICE(0x0b95, 0x1790),
 	.driver_info = (unsigned long)&ax88179_info,
 }, {
 	/* ASIX AX88178A 10/100/1000 */
-	USB_DEVICE_AND_INTERFACE_INFO(0x0b95, 0x178a, 0xff, 0xff, 0),
+	USB_DEVICE(0x0b95, 0x178a),
 	.driver_info = (unsigned long)&ax88178a_info,
 }, {
 	/* Cypress GX3 SuperSpeed to Gigabit Ethernet Bridge Controller */
-	USB_DEVICE_AND_INTERFACE_INFO(0x04b4, 0x3610, 0xff, 0xff, 0),
+	USB_DEVICE(0x04b4, 0x3610),
 	.driver_info = (unsigned long)&cypress_GX3_info,
 }, {
 	/* D-Link DUB-1312 USB 3.0 to Gigabit Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x2001, 0x4a00, 0xff, 0xff, 0),
+	USB_DEVICE(0x2001, 0x4a00),
 	.driver_info = (unsigned long)&dlink_dub1312_info,
 }, {
 	/* Sitecom USB 3.0 to Gigabit Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x0df6, 0x0072, 0xff, 0xff, 0),
+	USB_DEVICE(0x0df6, 0x0072),
 	.driver_info = (unsigned long)&sitecom_info,
 }, {
 	/* Samsung USB Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x04e8, 0xa100, 0xff, 0xff, 0),
+	USB_DEVICE(0x04e8, 0xa100),
 	.driver_info = (unsigned long)&samsung_info,
 }, {
 	/* Lenovo OneLinkDock Gigabit LAN */
-	USB_DEVICE_AND_INTERFACE_INFO(0x17ef, 0x304b, 0xff, 0xff, 0),
+	USB_DEVICE(0x17ef, 0x304b),
 	.driver_info = (unsigned long)&lenovo_info,
 }, {
 	/* Belkin B2B128 USB 3.0 Hub + Gigabit Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x050d, 0x0128, 0xff, 0xff, 0),
+	USB_DEVICE(0x050d, 0x0128),
 	.driver_info = (unsigned long)&belkin_info,
 }, {
 	/* Toshiba USB 3.0 GBit Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x0930, 0x0a13, 0xff, 0xff, 0),
+	USB_DEVICE(0x0930, 0x0a13),
 	.driver_info = (unsigned long)&toshiba_info,
 }, {
 	/* Magic Control Technology U3-A9003 USB 3.0 Gigabit Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x0711, 0x0179, 0xff, 0xff, 0),
+	USB_DEVICE(0x0711, 0x0179),
 	.driver_info = (unsigned long)&mct_info,
 }, {
 	/* Allied Telesis AT-UMC2000 USB 3.0/USB 3.1 Gen 1 to Gigabit Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x07c9, 0x000e, 0xff, 0xff, 0),
+	USB_DEVICE(0x07c9, 0x000e),
 	.driver_info = (unsigned long)&at_umc2000_info,
 }, {
 	/* Allied Telesis AT-UMC200 USB 3.0/USB 3.1 Gen 1 to Fast Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x07c9, 0x000f, 0xff, 0xff, 0),
+	USB_DEVICE(0x07c9, 0x000f),
 	.driver_info = (unsigned long)&at_umc200_info,
 }, {
 	/* Allied Telesis AT-UMC2000/SP USB 3.0/USB 3.1 Gen 1 to Gigabit Ethernet Adapter */
-	USB_DEVICE_AND_INTERFACE_INFO(0x07c9, 0x0010, 0xff, 0xff, 0),
+	USB_DEVICE(0x07c9, 0x0010),
 	.driver_info = (unsigned long)&at_umc2000sp_info,
 },
 	{ },
-- 
2.25.1

Re: [PATCH net v6 0/3] ax88179 driver optimization

[Jakub Kicinski]

On Fri, 17 Oct 2025 10:54:01 +0800 yicongsrfy@163.com wrote:
> This series of patches first fixes the issues related to the vendor
> driver, then reverts the previous changes to allow the vendor-specific
> driver to be loaded.

Discussion on v5 reads as an outright rejection, so I'm dropping this
from our review queue.
-- 
pw-bot: reject