kernel/linux.git/Documentation, branch v6.19.11

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

2026-04-02T11:25:44+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

2026-04-02T11:25:42+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

2026-04-02T11:25:36+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

ASoC: dt-bindings: stm32: Fix incorrect compatible string in stm32h7-sai match

2026-04-02T11:25:35+00:00

[ Upstream commit 91049ec2e18376ec2192e73ef7be4c7110436350 ] The conditional block that defines clock constraints for the stm32h7-sai variant references "st,stm32mph7-sai", which does not match any compatible string in the enum. As a result, clock validation for the h7 variant is silently skipped. Correct the compatible string to "st,stm32h7-sai". Fixes: 8509bb1f11a1f ("ASoC: dt-bindings: add stm32mp25 support for sai") Signed-off-by: Jihed Chaibi Reviewed-by: Olivier Moysan Link: https://patch.msgid.link/20260321012011.125791-1-jihed.chaibi.dev@gmail.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

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

2026-04-02T11:25:22+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

net: shaper: protect from late creation of hierarchy

2026-03-25T10:13:29+00:00

[ Upstream commit d75ec7e8ba1979a1eb0b9211d94d749cdce849c8 ] We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections. The netdev may get unregistered in between the time we take the ref and the time we lock it. We may allocate the hierarchy after flush has already run, which would lead to a leak. Take the instance lock in pre- already, this saves us from the race and removes the need for dedicated lock/unlock callbacks completely. After all, if there's any chance of write happening concurrently with the flush - we're back to leaking the hierarchy. We may take the lock for devices which don't support shapers but we're only dealing with SET operations here, not taking the lock would be optimizing for an error case. Fixes: 93954b40f6a4 ("net-shapers: implement NL set and delete operations") Link: https://lore.kernel.org/20260309173450.538026-1-p@1g4.org Signed-off-by: Jakub Kicinski Link: https://patch.msgid.link/20260317161014.779569-2-kuba@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

dt-bindings: display: msm: Fix reg ranges and clocks on Glymur

2026-03-19T15:15:26+00:00

commit 7403e87c138475a74e5176176778f391d847f42d upstream. The Glymur platform has four DisplayPort controllers. The hardware supports four streams (MST) per controller. However, on Glymur the first three controllers only have two streams wired to the display subsystem, while the fourth controller operates in single-stream mode. Add a dedicated clause for the Glymur compatible to require the register ranges for all four stream blocks, while allowing either one pixel clock (for the single-stream controller) or two pixel clocks (for the remaining controllers). Update the Glymur MDSS schema example by adding the missing p2, p3, mst2link and mst3link register blocks. Without these, the bindings validation fails. Also replace the made-up register addresses with the actual addresses from the first controller to match the SoC devicetree description. Cc: stable@vger.kernel.org # v6.19 Fixes: 8f63bf908213 ("dt-bindings: display: msm: Document the Glymur DiplayPort controller") Fixes: 1aee577bbc60 ("dt-bindings: display: msm: Document the Glymur Mobile Display SubSystem") Signed-off-by: Abel Vesa Reviewed-by: Krzysztof Kozlowski Patchwork: https://patchwork.freedesktop.org/patch/708518/ Link: https://lore.kernel.org/r/20260303-glymur-fix-dp-bindings-reg-clocks-v4-1-1ebd9c7c2cee@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov Signed-off-by: Greg Kroah-Hartman

KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM

2026-03-19T15:15:02+00:00

commit e2ffe85b6d2bb7780174b87aa4468a39be17eb81 upstream. 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: Greg Kroah-Hartman

dt-bindings: display/msm: qcom,sm8750-mdss: Fix model typo

2026-03-19T15:14:49+00:00

[ Upstream commit 4355b13d46f696d687f42b982efed7570e03e532 ] Fix obvious model typo (SM8650->SM8750) in the description. Signed-off-by: Krzysztof Kozlowski Fixes: 6b93840116df ("dt-bindings: display/msm: qcom,sm8750-mdss: Add SM8750") Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/707192/ Link: https://lore.kernel.org/r/20260225173419.125565-2-krzysztof.kozlowski@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

ALSA: doc: usb-audio: Add doc for QUIRK_FLAG_SKIP_IFACE_SETUP

2026-03-12T11:09:32+00:00

commit 93992667d0ab695ac30ceec91a516fd4bf725d75 upstream. QUIRK_FLAG_SKIP_IFACE_SETUP was introduced into usb-audio before without appropriate documentation, so add it. Fixes: 38c322068a26 ("ALSA: usb-audio: Add QUIRK_FLAG_SKIP_IFACE_SETUP") Cc: stable@vger.kernel.org Signed-off-by: Rong Zhang Link: https://patch.msgid.link/20260302173300.322673-1-i@rong.moe Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman