kernel/linux.git/drivers/usb/gadget/function/u_ether.h, branch v6.12.80

usb: gadget: f_ncm: Fix net_device lifecycle with device_move

2026-03-25T10:08:41+00:00

[ Upstream commit ec35c1969650e7cb6c8a91020e568ed46e3551b0 ] The network device outlived its parent gadget device during disconnection, resulting in dangling sysfs links and null pointer dereference problems. A prior attempt to solve this by removing SET_NETDEV_DEV entirely [1] was reverted due to power management ordering concerns and a NO-CARRIER regression. A subsequent attempt to defer net_device allocation to bind [2] broke 1:1 mapping between function instance and network device, making it impossible for configfs to report the resolved interface name. This results in a regression where the DHCP server fails on pmOS. Use device_move to reparent the net_device between the gadget device and /sys/devices/virtual/ across bind/unbind cycles. This preserves the network interface across USB reconnection, allowing the DHCP server to retain their binding. Introduce gether_attach_gadget()/gether_detach_gadget() helpers and use __free(detach_gadget) macro to undo attachment on bind failure. The bind_count ensures device_move executes only on the first bind. [1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/ [2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/ Fixes: 40d133d7f542 ("usb: gadget: f_ncm: convert to new function interface with backward compatibility") Cc: stable Signed-off-by: Kuen-Han Tsai Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-7-ea2afbc7d9b2@google.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

usb: gadget: add a inline function gether_bitrate()

2023-08-22T12:48:33+00:00

In function ecm_bitrate(), it is not support report bit rate for super speed plus mode, but it can use same bit rate value defined in ncm and rndis. Add a common inline function gether_bitrate() which report different for all possible speeds, it can be used by ecm, ncm and rndis, also remove old function from them. Signed-off-by: Linyu Yuan Link: https://lore.kernel.org/r/20230803091053.9714-3-quic_linyyuan@quicinc.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_ecm: Add suspend/resume and remote wakeup support

2023-03-29T08:27:01+00:00

When host sends suspend notification to the device, handle the suspend callbacks in the function driver. Depending on the remote wakeup capability the device can either trigger a remote wakeup or wait for the host initiated resume to resume data transfer. Signed-off-by: Elson Roy Serrao Reviewed-by: Thinh Nguyen Link: https://lore.kernel.org/r/1679694482-16430-7-git-send-email-quic_eserrao@quicinc.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: u_ether: support configuring interface names.

2021-01-15T15:08:53+00:00

This patch allows the administrator to configure the interface name of a function using u_ether (e.g., eem, ncm, rndis). Currently, all such interfaces, regardless of function type, are always called usb0, usb1, etc. This makes it very cumbersome to use more than one such type at a time, because userspace cannnot easily tell the interfaces apart and apply the right configuration to each one. Interface renaming in userspace based on driver doesn't help, because the interfaces all have the same driver. Without this patch, doing this require hacks/workarounds such as setting fixed MAC addresses on the functions, and then renaming by MAC address, or scraping configfs after each interface is created to find out what it is. Setting the interface name is done by writing to the same "ifname" configfs attribute that reports the interface name after the function is bound. The write must contain an interface pattern such as "usb%d" (which will cause the net core to pick the next available interface name starting with "usb"). This patch does not allow writing an exact interface name (as opposed to a pattern) because if the interface already exists at bind time, the bind will fail and the whole gadget will fail to activate. This could be allowed in a future patch. For compatibility with current userspace, when reading an ifname that has not currently been set, the result is still "(unnamed net_device)". Once a write to ifname happens, then reading ifname will return whatever was last written. Tested by configuring an rndis function and an ncm function on the same gadget, and writing "rndis%d" to ifname on the rndis function and "ncm%d" to ifname on the ncm function. When the gadget was bound, the rndis interface was rndis0 and the ncm interface was ncm0. Signed-off-by: Lorenzo Colitti Link: https://lore.kernel.org/r/20210113234222.3272933-1-lorenzo@google.com Signed-off-by: Greg Kroah-Hartman

USB: gadget: Use the correct style for SPDX License Identifier

2020-05-05T07:58:49+00:00

This patch corrects the SPDX License Identifier style in header files related to USB peripheral controller drivers. For C header files Documentation/process/license-rules.rst mandates C-like comments (opposed to C source files where C++ style should be used). Changes made by using a script provided by Joe Perches here: https://lkml.org/lkml/2019/2/7/46. Suggested-by: Joe Perches Signed-off-by: Nishad Kamdar Signed-off-by: Felipe Balbi

USB: gadget: function: Remove redundant license text

2017-11-07T14:45:02+00:00

Now that the SPDX tag is in all USB files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Oliver Neukum Cc: Johan Hovold Cc: Jerry Zhang Cc: John Keeping Cc: Krzysztof Opasiak Cc: Abdulhadi Mohamed Cc: Matthew Wilcox Cc: Janusz Dziedzic Acked-by: Felipe Balbi Acked-by: Michal Nazarewicz Acked-by: Laurent Pinchart Acked-by: Vincent Pelletier Signed-off-by: Greg Kroah-Hartman

USB: add SPDX identifiers to all remaining files in drivers/usb/

2017-11-04T10:48:02+00:00

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/usb/ and include/linux/usb* files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Acked-by: Felipe Balbi Acked-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_ncm/u_ether: Move 'SKB reserve' quirk setup to u_ether

2017-08-18T09:29:10+00:00

That quirk is required to make USB Ethernet gadget working on HW that can't cope with unaligned DMA. For some reason only f_ncm sets up that quirk, let's setup it directly in u_ether so other network models would have that quirk applied as well. All network models have been tested with ChipIdea UDC driver on NVIDIA Tegra20 SoC that require DMA to be aligned. Signed-off-by: Dmitry Osipenko Signed-off-by: Felipe Balbi

usb: gadget: u_ether: add a flag to avoid skb_reserve() calling

2016-08-31T07:06:03+00:00

This patch adds a flag "no_skb_reserve" in struct eth_dev. So, if a peripheral driver sets the quirk_avoids_skb_reserve flag, upper network gadget drivers (e.g. f_ncm.c) can avoid skb_reserve() calling using the flag as well. Signed-off-by: Yoshihiro Shimoda Signed-off-by: Felipe Balbi

usb: gadget: remove gadget_chips.h

2015-08-06T14:35:20+00:00

This header file contains helpers for quirks based on UDC controller name. Since we have generic quirk bitfields in usb_gadget structure for all of these quirks we don't need to have this header any longer. This patch removes gadget_chips.h file and makes sure that it's no longer included anywhere in kernel sources. Signed-off-by: Robert Baldyga Signed-off-by: Felipe Balbi