linux.git/Documentation, branch v6.12.81

dt-bindings: connector: add pd-disable dependency

2026-04-11T12:24:47+00:00

commit 269c26464dcf8b54b0dd9c333721c30ee44ae297 upstream.

When Power Delivery is not supported, the source is unable to obtain the
current capability from the Source PDO. As a result, typec-power-opmode
needs to be added to advertise such capability.

Acked-by: Conor Dooley 
Cc: stable 
Signed-off-by: Xu Yang 
Link: https://patch.msgid.link/20260330063518.719345-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman

dt-bindings: gpio: fix microchip #interrupt-cells

2026-04-11T12:24:38+00:00

[ Upstream commit 6b5ef8c88854b343b733b574ea8754c9dab61f41 ]

The GPIO controller on PolarFire SoC supports more than one type of
interrupt and needs two interrupt cells.

Fixes: 735806d8a68e9 ("dt-bindings: gpio: add bindings for microchip mpfs gpio")
Signed-off-by: Jamie Gibbons 
Signed-off-by: Conor Dooley 
Link: https://patch.msgid.link/20260326-wise-gumdrop-49217723a72a@spud
Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Sasha Levin

dt-bindings: auxdisplay: ht16k33: Use unevaluatedProperties to fix common property warning

2026-04-11T12:24:30+00:00

[ Upstream commit 398c0c8bbc8f5a9d2f43863275a427a9d3720b6f ]

Change additionalProperties to unevaluatedProperties because it refs to
/schemas/input/matrix-keymap.yaml.

Fix below CHECK_DTBS warnings:
arch/arm/boot/dts/nxp/imx/imx6dl-victgo.dtb: keypad@70 (holtek,ht16k33): 'keypad,num-columns', 'keypad,num-rows' do not match any of the regexes: '^pinctrl-[0-9]+$'
        from schema $id: http://devicetree.org/schemas/auxdisplay/holtek,ht16k33.yaml#

Fixes: f12b457c6b25c ("dt-bindings: auxdisplay: ht16k33: Convert to json-schema")
Acked-by: Rob Herring (Arm) 
Signed-off-by: Frank Li 
Signed-off-by: Andy Shevchenko 
Signed-off-by: Sasha Levin

ovl: make fsync after metadata copy-up opt-in mount option

2026-04-02T11:09:50+00:00

commit 1f6ee9be92f8df85a8c9a5a78c20fd39c0c21a95 upstream.

Commit 7d6899fb69d25 ("ovl: fsync after metadata copy-up") was done to
fix durability of overlayfs copy up on an upper filesystem which does
not enforce ordering on storing of metadata changes (e.g. ubifs).

In an earlier revision of the regressing commit by Lei Lv, the metadata
fsync behavior was opt-in via a new "fsync=strict" mount option.
We were hoping that the opt-in mount option could be avoided, so the
change was only made to depend on metacopy=off, in the hope of not
hurting performance of metadata heavy workloads, which are more likely
to be using metacopy=on.

This hope was proven wrong by a performance regression report from Google
COS workload after upgrade to kernel 6.12.

This is an adaptation of Lei's original "fsync=strict" mount option
to the existing upstream code.

The new mount option is mutually exclusive with the "volatile" mount
option, so the latter is now an alias to the "fsync=volatile" mount
option.

Reported-by: Chenglong Tang 
Closes: https://lore.kernel.org/linux-unionfs/CAOdxtTadAFH01Vui1FvWfcmQ8jH1O45owTzUcpYbNvBxnLeM7Q@mail.gmail.com/
Link: https://lore.kernel.org/linux-unionfs/CAOQ4uxgKC1SgjMWre=fUb00v8rxtd6sQi-S+dxR8oDzAuiGu8g@mail.gmail.com/
Fixes: 7d6899fb69d25 ("ovl: fsync after metadata copy-up")
Depends: 50e638beb67e0 ("ovl: Use str_on_off() helper in ovl_show_options()")
Cc: stable@vger.kernel.org # v6.12+
Signed-off-by: Fei Lv 
Signed-off-by: Amir Goldstein 
Signed-off-by: Greg Kroah-Hartman

hwmon: (peci/cputemp) Fix crit_hyst returning delta instead of absolute temperature

2026-04-02T11:09:43+00:00

commit 0adc752b4f7d82af7bd14f7cad3091b3b5d702ba upstream.

The hwmon sysfs ABI expects tempN_crit_hyst to report the temperature at
which the critical condition clears, not the hysteresis delta from the
critical limit.

The peci cputemp driver currently returns tjmax - tcontrol for
crit_hyst_type, which is the hysteresis margin rather than the
corresponding absolute temperature.

Return tcontrol directly, and update the documentation accordingly.

Fixes: bf3608f338e9 ("hwmon: peci: Add cputemp driver")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260323002352.93417-2-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

hwmon: (adm1177) fix sysfs ABI violation and current unit conversion

2026-04-02T11:09:40+00:00

[ Upstream commit bf08749a6abb6d1959bfdc0edc32c640df407558 ]

The adm1177 driver exposes the current alert threshold through
hwmon_curr_max_alarm. This violates the hwmon sysfs ABI, where
*_alarm attributes are read-only status flags and writable thresholds
must use currN_max.

The driver also stores the threshold internally in microamps, while
currN_max is defined in milliamps. Convert the threshold accordingly
on both the read and write paths.

Widen the cached threshold and related calculations to 64 bits so
that small shunt resistor values do not cause truncation or overflow.
Also use 64-bit arithmetic for the mA/uA conversions, clamp writes
to the range the hardware can represent, and propagate failures from
adm1177_write_alert_thr() instead of silently ignoring them.

Update the hwmon documentation to reflect the attribute rename and
the correct units returned by the driver.

Fixes: 09b08ac9e8d5 ("hwmon: (adm1177) Add ADM1177 Hot Swap Controller and Digital Power Monitor driver")
Signed-off-by: Sanman Pradhan 
Acked-by: Nuno Sá 
Link: https://lore.kernel.org/r/20260325051246.28262-1-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck 
Signed-off-by: Sasha Levin

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

2026-04-02T11:09:30+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

KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM

2026-03-25T10:08:43+00:00

[ Upstream commit e2ffe85b6d2bb7780174b87aa4468a39be17eb81 ]

Add KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM to allow L1 to set
FREEZE_IN_SMM in vmcs12's GUEST_IA32_DEBUGCTL field, as permitted
prior to commit 6b1dd26544d0 ("KVM: VMX: Preserve host's
DEBUGCTLMSR_FREEZE_IN_SMM while running the guest").  Enable the quirk
by default for backwards compatibility (like all quirks); userspace
can disable it via KVM_CAP_DISABLE_QUIRKS2 for consistency with the
constraints on WRMSR(IA32_DEBUGCTL).

Note that the quirk only bypasses the consistency check.  The vmcs02 bit is
still owned by the host, and PMCs are not frozen during virtualized SMM.
In particular, if a host administrator decides that PMCs should not be
frozen during physical SMM, then L1 has no say in the matter.

Fixes: 095686e6fcb4 ("KVM: nVMX: Check vmcs12->guest_ia32_debugctl on nested VM-Enter")
Cc: stable@vger.kernel.org
Signed-off-by: Jim Mattson 
Link: https://patch.msgid.link/20260205231537.1278753-1-jmattson@google.com
[sean: tag for stable@, clean-up and fix goofs in the comment and docs]
Signed-off-by: Sean Christopherson 
[Rename quirk. - Paolo]
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Introduce Intel specific quirk KVM_X86_QUIRK_IGNORE_GUEST_PAT

2026-03-25T10:08:43+00:00

[ Upstream commit c9c1e20b4c7d60fa084b3257525d21a49fe651a1 ]

Introduce an Intel specific quirk KVM_X86_QUIRK_IGNORE_GUEST_PAT to have
KVM ignore guest PAT when this quirk is enabled.

On AMD platforms, KVM always honors guest PAT.  On Intel however there are
two issues.  First, KVM *cannot* honor guest PAT if CPU feature self-snoop
is not supported. Second, UC access on certain Intel platforms can be very
slow[1] and honoring guest PAT on those platforms may break some old
guests that accidentally specify video RAM as UC. Those old guests may
never expect the slowness since KVM always forces WB previously. See [2].

So, introduce a quirk that KVM can enable by default on all Intel platforms
to avoid breaking old unmodifiable guests. Newer userspace can disable this
quirk if it wishes KVM to honor guest PAT; disabling the quirk will fail
if self-snoop is not supported, i.e. if KVM cannot obey the wish.

The quirk is a no-op on AMD and also if any assigned devices have
non-coherent DMA.  This is not an issue, as KVM_X86_QUIRK_CD_NW_CLEARED is
another example of a quirk that is sometimes automatically disabled.

Suggested-by: Paolo Bonzini 
Suggested-by: Sean Christopherson 
Cc: Kevin Tian 
Signed-off-by: Yan Zhao 
Link: https://lore.kernel.org/all/Ztl9NWCOupNfVaCA@yzhao56-desk.sh.intel.com # [1]
Link: https://lore.kernel.org/all/87jzfutmfc.fsf@redhat.com # [2]
Message-ID: <20250224070946.31482-1-yan.y.zhao@intel.com>
[Use supported_quirks/inapplicable_quirks to support both AMD and
 no-self-snoop cases, as well as to remove the shadow_memtype_mask check
 from kvm_mmu_may_ignore_guest_pat(). - Paolo]
Signed-off-by: Paolo Bonzini 
Stable-dep-of: e2ffe85b6d2b ("KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration

2026-03-25T10:08:43+00:00

[ Upstream commit dcb988cdac85bad177de86fbf409524eda4f9467 ]

Add a quirk to control KVM's misguided initialization of select feature
MSRs to KVM's max configuration, as enabling features by default violates
KVM's approach of letting userspace own the vCPU model, and is actively
problematic for MSRs that are conditionally supported, as the vCPU will
end up with an MSR value that userspace can't restore.  E.g. if the vCPU
is configured with PDCM=0, userspace will save and attempt to restore a
non-zero PERF_CAPABILITIES, thanks to KVM's meddling.

Link: https://lore.kernel.org/r/20240802185511.305849-4-seanjc@google.com
Signed-off-by: Sean Christopherson 
Stable-dep-of: e2ffe85b6d2b ("KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman