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: 40d133d7f5 ("usb: gadget: f_ncm: convert to new function interface with backward compatibility")
Cc: stable <stable@kernel.org>
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-7-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit e065c6a7e4.
This commit is being reverted as part of a series-wide revert.
By deferring the net_device allocation to the bind() phase, a single
function instance will spawn multiple network devices if it is symlinked
to multiple USB configurations.
This causes regressions for userspace tools (like the postmarketOS DHCP
daemon) that rely on reading the interface name (e.g., "usb0") from
configfs. Currently, configfs returns the template "usb%d", causing the
userspace network setup to fail.
Crucially, because this patch breaks the 1:1 mapping between the
function instance and the network device, this naming issue cannot
simply be patched. Configfs only exposes a single 'ifname' attribute per
instance, making it impossible to accurately report the actual interface
name when multiple underlying network devices can exist for that single
instance.
All configurations tied to the same function instance are meant to share
a single network device. Revert this change to restore the 1:1 mapping
by allocating the network device at the instance level (alloc_inst).
Reported-by: David Heidelberg <david@ixit.cz>
Closes: https://lore.kernel.org/linux-usb/70b558ea-a12e-4170-9b8e-c951131249af@ixit.cz/
Fixes: 56a512a9b4 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable <stable@kernel.org>
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-6-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 0c0981126b.
This commit is being reverted as part of a series-wide revert.
By deferring the net_device allocation to the bind() phase, a single
function instance will spawn multiple network devices if it is symlinked
to multiple USB configurations.
This causes regressions for userspace tools (like the postmarketOS DHCP
daemon) that rely on reading the interface name (e.g., "usb0") from
configfs. Currently, configfs returns the template "usb%d", causing the
userspace network setup to fail.
Crucially, because this patch breaks the 1:1 mapping between the
function instance and the network device, this naming issue cannot
simply be patched. Configfs only exposes a single 'ifname' attribute per
instance, making it impossible to accurately report the actual interface
name when multiple underlying network devices can exist for that single
instance.
All configurations tied to the same function instance are meant to share
a single network device. Revert this change to restore the 1:1 mapping
by allocating the network device at the instance level (alloc_inst).
Reported-by: David Heidelberg <david@ixit.cz>
Closes: https://lore.kernel.org/linux-usb/70b558ea-a12e-4170-9b8e-c951131249af@ixit.cz/
Fixes: 56a512a9b4 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable <stable@kernel.org>
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-4-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The net_device in the u_ether framework currently requires explicit
calls to unregister and free the device.
Introduce gether_unregister_free_netdev() and the corresponding
auto-cleanup macro. This ensures that if a net_device is registered, it
is properly unregistered and the associated work queue is flushed before
the memory is freed.
This is a preparatory patch to simplify error handling paths in gadget
drivers by removing the need for explicit goto labels for net_device
cleanup.
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Link: https://patch.msgid.link/20251230-ncm-refactor-v1-2-793e347bc7a7@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the net_device is allocated when the function instance is
created (e.g., in ncm_alloc_inst()). While this allows userspace to
configure the device early, it decouples the net_device lifecycle from
the actual USB connection state (bind/unbind). The goal is to defer
net_device creation to the bind callback to properly align the lifecycle
with its parent gadget device.
However, deferring net_device allocation would prevent userspace from
configuring parameters (like interface name or MAC address) before the
net_device exists.
Introduce a new structure, struct gether_opts, associated with the
usb_function_instance, to cache settings independently of the
net_device. These settings include the interface name pattern, MAC
addresses (device and host), queue multiplier, and address assignment
type.
New helper functions are added:
- gether_setup_opts_default(): Initializes struct gether_opts with
defaults, including random MAC addresses.
- gether_apply_opts(): Applies the cached options from a struct
gether_opts to a valid net_device.
To expose these options to userspace, new configfs macros
(USB_ETHER_OPTS_ITEM and USB_ETHER_OPTS_ATTR_*) are defined in
u_ether_configfs.h. These attributes are part of the function
instance's configfs group.
This refactoring is a preparatory step. It allows the subsequent patch
to safely move the net_device allocation from the instance creation
phase to the bind phase without losing the ability to pre-configure
the interface via configfs.
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Link: https://patch.msgid.link/20251230-ncm-refactor-v1-1-793e347bc7a7@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-3-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <lorenzo@google.com>
Link: https://lore.kernel.org/r/20210113234222.3272933-1-lorenzo@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
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 <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <digetx@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
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 <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
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 <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Replace calls of gadget_supports_altsettings() function (which check altset
support by comparing UDC controller name with hardcoded names) with
gadget_is_altset_supported() which checks generic quirk bitfield.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
The drivers/usb/gadget directory contains many files.
Files which are related can be distributed into separate directories.
This patch moves the USB functions implementations into a separate directory.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
