linux.git/drivers/usb, branch v6.18.21

usb: core: new quirk to handle devices with zero configurations

2026-04-02T11:23:01+00:00

[ Upstream commit 9f6a983cfa22ac662c86e60816d3a357d4b551e9 ]

Some USB devices incorrectly report bNumConfigurations as 0 in their
device descriptor, which causes the USB core to reject them during
enumeration.
logs:
usb 1-2: device descriptor read/64, error -71
usb 1-2: no configurations
usb 1-2: can't read configurations, error -22

However, these devices actually work correctly when
treated as having a single configuration.

Add a new quirk USB_QUIRK_FORCE_ONE_CONFIG to handle such devices.
When this quirk is set, assume the device has 1 configuration instead
of failing with -EINVAL.

This quirk is applied to the device with VID:PID 5131:2007 which
exhibits this behavior.

Signed-off-by: Jie Deng 
Link: https://patch.msgid.link/20260227084931.1527461-1-dengjie03@kylinos.cn
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

USB: serial: f81232: fix incomplete serial port generation

2026-03-25T10:10:43+00:00

commit cd644b805da8a253198718741bf363c4c58862ff upstream.

The Fintek F81532A/534A/535/536 family relies on the
F81534A_CTRL_CMD_ENABLE_PORT (116h) register during initialization to
both determine serial port status and control port creation. If the
driver experiences fast load/unload cycles, the device state may becomes
unstable, resulting in the incomplete generation of serial ports.

Performing a dummy read operation on the register prior to the initial
write command resolves the issue. This clears the device's stale internal
state. Subsequent write operations will correctly generate all serial
ports.

This patch also removes the retry loop in f81534a_ctrl_set_register()
because the stale state has been fixed.

Tested on: HygonDM1SLT(Hygon C86 3250 8-core Processor)

Signed-off-by: Ji-Ze Hong (Peter Hong) 
Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

Revert "tcpm: allow looking for role_sw device in the main node"

2026-03-19T15:08:31+00:00

commit 6b275bfaa16be3fb1689fa6794e445ecd127a1b4 upstream.

This reverts commit 1366cd228b0c67b60a2c0c26ef37fe9f7cfedb7f.

The fwnode_usb_role_switch_get() returns NULL only if no connection is
found, returns ERR_PTR(-EPROBE_DEFER) if connection is found but deferred
probe is needed, or a valid pointer of usb_role_switch.

When switching from a NULL check to IS_ERR_OR_NULL(), usb_role_switch_get()
returns NULL and overwrites the ERR_PTR(-EPROBE_DEFER) returned by
fwnode_usb_role_switch_get(). This causes the deferred probe indication to
be lost, preventing the USB role switch from ever being retrieved.

Fixes: 1366cd228b0c ("tcpm: allow looking for role_sw device in the main node")
Cc: stable 
Signed-off-by: Xu Yang 
Tested-by: Arnaud Ferraris 
Reviewed-by: Heikki Krogerus 
Link: https://patch.msgid.link/20260309074313.2809867-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_ncm: Fix net_device lifecycle with device_move

2026-03-19T15:08:28+00:00

commit ec35c1969650e7cb6c8a91020e568ed46e3551b0 upstream.

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

Revert "usb: gadget: u_ether: add gether_opts for config caching"

2026-03-19T15:08:28+00:00

commit 3131c1aff7cdffb96239f06f98e16188cbc2083f upstream.

This reverts commit e065c6a7e46c2ee9c677fdbf50035323d2de1215.

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 
Closes: https://lore.kernel.org/linux-usb/70b558ea-a12e-4170-9b8e-c951131249af@ixit.cz/
Fixes: 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable 
Signed-off-by: Kuen-Han Tsai 
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-6-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman

Revert "usb: gadget: f_ncm: align net_device lifecycle with bind/unbind"

2026-03-19T15:08:28+00:00

commit 37893bc5de2460c543ec1aa8250c37a305234054 upstream.

This reverts commit 56a512a9b4107079f68701e7d55da8507eb963d9.

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 
Closes: https://lore.kernel.org/linux-usb/70b558ea-a12e-4170-9b8e-c951131249af@ixit.cz/
Fixes: 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable 
Signed-off-by: Kuen-Han Tsai 
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-3-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman

Revert "usb: gadget: u_ether: Add auto-cleanup helper for freeing net_device"

2026-03-19T15:08:28+00:00

commit 46662d3a1ad40282ba9f753cccc6f909ec4468cc upstream.

This reverts commit 0c0981126b99288ed354d3d414c8a5fd42ac9e25.

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 
Closes: https://lore.kernel.org/linux-usb/70b558ea-a12e-4170-9b8e-c951131249af@ixit.cz/
Fixes: 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable 
Signed-off-by: Kuen-Han Tsai 
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-4-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman

Revert "usb: legacy: ncm: Fix NPE in gncm_bind"

2026-03-19T15:08:28+00:00

commit f2524c0e6ff0a5f72f1e1a32441c69d3b56430c4 upstream.

This reverts commit fde0634ad9856b3943a2d1a8cc8de174a63ac840.

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 
Closes: https://lore.kernel.org/linux-usb/70b558ea-a12e-4170-9b8e-c951131249af@ixit.cz/
Fixes: 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable 
Signed-off-by: Kuen-Han Tsai 
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-2-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman

Revert "usb: gadget: f_ncm: Fix atomic context locking issue"

2026-03-19T15:08:28+00:00

commit 11199720fac2debbe718aec11e026ab3330dc80d upstream.

This reverts commit 0d6c8144ca4d93253de952a5ea0028c19ed7ab68.

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 
Closes: https://lore.kernel.org/linux-usb/70b558ea-a12e-4170-9b8e-c951131249af@ixit.cz/
Fixes: 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable 
Signed-off-by: Kuen-Han Tsai 
Link: https://patch.msgid.link/20260309-f-ncm-revert-v2-1-ea2afbc7d9b2@google.com
Signed-off-by: Greg Kroah-Hartman

usb: legacy: ncm: Fix NPE in gncm_bind

2026-03-19T15:08:28+00:00

commit fde0634ad9856b3943a2d1a8cc8de174a63ac840 upstream.

Commit 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle
with bind/unbind") deferred the allocation of the net_device. This
change leads to a NULL pointer dereference in the legacy NCM driver as
it attempts to access the net_device before it's fully instantiated.

Store the provided qmult, host_addr, and dev_addr into the struct
ncm_opts->net_opts during gncm_bind(). These values will be properly
applied to the net_device when it is allocated and configured later in
the binding process by the NCM function driver.

Fixes: 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable@kernel.org
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-lkp/202602181727.fd76c561-lkp@intel.com
Signed-off-by: Kuen-Han Tsai 
Link: https://patch.msgid.link/20260221-legacy-ncm-v2-1-dfb891d76507@google.com
Signed-off-by: Greg Kroah-Hartman