netdev - RE: RTL8156(A|B) chip requires r8156 to be force loaded to operate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <1e6d7b8c3af444ae900fd4248f2a9d35@realtek.com>
Date:   Fri, 14 Jan 2022 06:29:28 +0000
From:   Hayes Wang <hayeswang@...ltek.com>
To:     Jakub Kicinski <kuba@...nel.org>, Ryan Lahfa <ryan@...fa.xyz>
CC:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        Andreas Seiderer <x64multicore@...glemail.com>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>
Subject: RE: RTL8156(A|B) chip requires r8156 to be force loaded to operate

Jakub Kicinski <kuba@...nel.org>
> Sent: Friday, January 14, 2022 12:17 PM
[...]
> Dunno much about USB but it seems the driver matches:
> 
> 	USB_DEVICE_INTERFACE_CLASS(vend, prod, USB_CLASS_VENDOR_SPEC),
> \
> 
> and
> 
> 	USB_DEVICE_AND_INTERFACE_INFO(vend, prod, USB_CLASS_COMM, \
> 			USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE), \
> 
> Both of these should match. Former because:
> 
> Bus 002 Device 002: ID 0bda:8156 Realtek Semiconductor Corp. USB
> 10/100/1G/2.5G LAN
> [...]
>      Interface Descriptor:
>        bLength                 9
>        bDescriptorType         4
>        bInterfaceNumber        0
>        bAlternateSetting       0
>        bNumEndpoints           3
>        bInterfaceClass       255 Vendor Specific Class
>        bInterfaceSubClass    255 Vendor Specific Subclass
> 
> And the latter because of another config with:
> 
>        bInterfaceClass         2 Communications
>        bInterfaceSubClass      6 Ethernet Networking
>        bInterfaceProtocol      0

There are three configurations for RTL8156.
	config #1: vendor mode (r8152)
	config #2: NCM mode (cdc_ncm)
	config #3: ECM mode (cdc_ether)

The USB core selects config #2 for default, so cdc_ncm is loaded.
If you plan to use vendor mode, you have to switch the configuration
to config #1. For example,

	echo 1 > /sys/bus/usb/devices/2-7/bConfigurationValue

Best Regards,
Hayes