kernel/linux.git/drivers/leds/led-class.c, branch v6.18.22

leds: led-class: Only Add LED to leds_list when it is fully ready

2026-01-30T09:32:22+00:00

commit d1883cefd31752f0504b94c3bcfa1f6d511d6e87 upstream. Before this change the LED was added to leds_list before led_init_core() gets called adding it the list before led_classdev.set_brightness_work gets initialized. This leaves a window where led_trigger_register() of a LED's default trigger will call led_trigger_set() which calls led_set_brightness() which in turn will end up queueing the *uninitialized* led_classdev.set_brightness_work. This race gets hit by the lenovo-thinkpad-t14s EC driver which registers 2 LEDs with a default trigger provided by snd_ctl_led.ko in quick succession. The first led_classdev_register() causes an async modprobe of snd_ctl_led to run and that async modprobe manages to exactly hit the window where the second LED is on the leds_list without led_init_core() being called for it, resulting in: ------------[ cut here ]------------ WARNING: CPU: 11 PID: 5608 at kernel/workqueue.c:4234 __flush_work+0x344/0x390 Hardware name: LENOVO 21N2S01F0B/21N2S01F0B, BIOS N42ET93W (2.23 ) 09/01/2025 ... Call trace: __flush_work+0x344/0x390 (P) flush_work+0x2c/0x50 led_trigger_set+0x1c8/0x340 led_trigger_register+0x17c/0x1c0 led_trigger_register_simple+0x84/0xe8 snd_ctl_led_init+0x40/0xf88 [snd_ctl_led] do_one_initcall+0x5c/0x318 do_init_module+0x9c/0x2b8 load_module+0x7e0/0x998 Close the race window by moving the adding of the LED to leds_list to after the led_init_core() call. Cc: stable@vger.kernel.org Fixes: d23a22a74fde ("leds: delay led_set_brightness if stopping soft-blink") Signed-off-by: Hans de Goede Reviewed-by: Sebastian Reichel Link: https://patch.msgid.link/20251211163727.366441-1-johannes.goede@oss.qualcomm.com Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman

leds: led-class: Add Device Tree support to led_get()

2025-09-16T15:49:28+00:00

Add 'name' argument to of_led_get() such that it can lookup LEDs in devicetree by either name or index. And use this modified function to add devicetree support to the generic (non devicetree specific) [devm_]led_get() function. This uses the standard devicetree pattern of adding a -names string array to map names to the indexes for an array of resources. Reviewed-by: Andy Shevchenko Reviewed-by: Linus Walleij Signed-off-by: Hans de Goede Signed-off-by: Aleksandrs Vinarskis Link: https://lore.kernel.org/r/20250910-leds-v5-3-bb90a0f897d5@vinarskis.com Signed-off-by: Lee Jones

Merge tag 'leds-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds

2025-07-31T18:54:01+00:00

Pull LED updates from Lee Jones: "Improvements & Fixes: - A fix for QCOM Flash to prevent incorrect register access when the driver is re-bound. This is solved by duplicating a static register array during the probe function, which prevents register addresses from being miscalculated after multiple binds - The LP50xx driver now correctly handles the 'reg' property in device tree child nodes to ensure the multi_index is set correctly. This prevents issues where LEDs could be controlled incorrectly if the device tree nodes were processed in a different order. An error is returned if the reg property is missing or out of range - Add a Kconfig dependency on between TPS6131x and V4L2_FLASH_LED_CLASS to prevent a build failure when the driver is built-in and the V4L2 flash infrastructure is a loadable module - Fix a potential buffer overflow warning in PCA955x reported by older GCC versions by using a more precise format specifier when creating the default LED label. Cleanups & Refactoring: - Correct the MAINTAINERS file entry for the TPS6131X flash LED driver to point to the correct device tree binding file name - Fix a comment in the Flash Class for the flash_timeout setter to "flash timeout" from "flash duration" for accuracy - The of_led_get() function is no longer exported as it has no users outside of its own module. Removals: - Revert the commit to configure LED blink intervals for hardware offload in the Netdev Trigger. This change was found to break existing PHY drivers by putting their LEDs into a permanent, unconditional blinking state. Device Tree Bindings Updates: - Update the binding for LP50xx to document that the child reg property is the index within the LED bank. The example was also updated to use correct values - Update the JNCP5623 binding to add 0x39 as a valid I2C address, as it is used by the NCP5623C variant" * tag 'leds-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds: dt-bindings: leds: ncp5623: Add 0x39 as a valid I2C address Revert "leds: trigger: netdev: Configure LED blink interval for HW offload" leds: pca955x: Avoid potential overflow when filling default_label (take 2) leds: Unexport of_led_get() leds: tps6131x: Add V4L2_FLASH_LED_CLASS dependency dt-bindings: leds: lp50xx: Document child reg, fix example leds: leds-lp50xx: Handle reg to get correct multi_index leds: led-class-flash:: Fix flash_timeout comment MAINTAINERS: Adjust file entry in TPS6131X FLASH LED DRIVER leds: flash: leds-qcom-flash: Fix registry access after re-bind

leds: Unexport of_led_get()

2025-07-02T16:18:01+00:00

There are no users outside the module. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250630092639.1574860-1-andriy.shevchenko@linux.intel.com Signed-off-by: Lee Jones

sysfs: treewide: switch back to attribute_group::bin_attrs

2025-06-17T08:44:15+00:00

The normal bin_attrs field can now handle const pointers. This makes the _new variant unnecessary. Switch all users back. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20250530-sysfs-const-bin_attr-final-v3-4-724bfcf05b99@weissschuh.net Signed-off-by: Greg Kroah-Hartman

leds: triggers: Constify 'struct bin_attribute'

2025-01-09T11:09:09+00:00

The sysfs core now allows instances of 'struct bin_attribute' to be moved into read-only memory. Make use of that to protect them against accidental or malicious modifications. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20241222-sysfs-const-bin_attr-led-v1-1-ecc5212a31fa@weissschuh.net Signed-off-by: Lee Jones

leds: class: Protect brightness_show() with led_cdev->led_access mutex

2024-11-06T08:42:59+00:00

There is NULL pointer issue observed if from Process A where hid device being added which results in adding a led_cdev addition and later a another call to access of led_cdev attribute from Process B can result in NULL pointer issue. Use mutex led_cdev->led_access to protect access to led->cdev and its attribute inside brightness_show() and max_brightness_show() and also update the comment for mutex that it should be used to protect the led class device fields. Process A Process B kthread+0x114 worker_thread+0x244 process_scheduled_works+0x248 uhid_device_add_worker+0x24 hid_add_device+0x120 device_add+0x268 bus_probe_device+0x94 device_initial_probe+0x14 __device_attach+0xfc bus_for_each_drv+0x10c __device_attach_driver+0x14c driver_probe_device+0x3c __driver_probe_device+0xa0 really_probe+0x190 hid_device_probe+0x130 ps_probe+0x990 ps_led_register+0x94 devm_led_classdev_register_ext+0x58 led_classdev_register_ext+0x1f8 device_create_with_groups+0x48 device_create_groups_vargs+0xc8 device_add+0x244 kobject_uevent+0x14 kobject_uevent_env[jt]+0x224 mutex_unlock[jt]+0xc4 __mutex_unlock_slowpath+0xd4 wake_up_q+0x70 try_to_wake_up[jt]+0x48c preempt_schedule_common+0x28 __schedule+0x628 __switch_to+0x174 el0t_64_sync+0x1a8/0x1ac el0t_64_sync_handler+0x68/0xbc el0_svc+0x38/0x68 do_el0_svc+0x1c/0x28 el0_svc_common+0x80/0xe0 invoke_syscall+0x58/0x114 __arm64_sys_read+0x1c/0x2c ksys_read+0x78/0xe8 vfs_read+0x1e0/0x2c8 kernfs_fop_read_iter+0x68/0x1b4 seq_read_iter+0x158/0x4ec kernfs_seq_show+0x44/0x54 sysfs_kf_seq_show+0xb4/0x130 dev_attr_show+0x38/0x74 brightness_show+0x20/0x4c dualshock4_led_get_brightness+0xc/0x74 [ 3313.874295][ T4013] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060 [ 3313.874301][ T4013] Mem abort info: [ 3313.874303][ T4013] ESR = 0x0000000096000006 [ 3313.874305][ T4013] EC = 0x25: DABT (current EL), IL = 32 bits [ 3313.874307][ T4013] SET = 0, FnV = 0 [ 3313.874309][ T4013] EA = 0, S1PTW = 0 [ 3313.874311][ T4013] FSC = 0x06: level 2 translation fault [ 3313.874313][ T4013] Data abort info: [ 3313.874314][ T4013] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 [ 3313.874316][ T4013] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 3313.874318][ T4013] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 3313.874320][ T4013] user pgtable: 4k pages, 39-bit VAs, pgdp=00000008f2b0a000 .. [ 3313.874332][ T4013] Dumping ftrace buffer: [ 3313.874334][ T4013] (ftrace buffer empty) .. .. [ dd3313.874639][ T4013] CPU: 6 PID: 4013 Comm: InputReader [ 3313.874648][ T4013] pc : dualshock4_led_get_brightness+0xc/0x74 [ 3313.874653][ T4013] lr : led_update_brightness+0x38/0x60 [ 3313.874656][ T4013] sp : ffffffc0b910bbd0 .. .. [ 3313.874685][ T4013] Call trace: [ 3313.874687][ T4013] dualshock4_led_get_brightness+0xc/0x74 [ 3313.874690][ T4013] brightness_show+0x20/0x4c [ 3313.874692][ T4013] dev_attr_show+0x38/0x74 [ 3313.874696][ T4013] sysfs_kf_seq_show+0xb4/0x130 [ 3313.874700][ T4013] kernfs_seq_show+0x44/0x54 [ 3313.874703][ T4013] seq_read_iter+0x158/0x4ec [ 3313.874705][ T4013] kernfs_fop_read_iter+0x68/0x1b4 [ 3313.874708][ T4013] vfs_read+0x1e0/0x2c8 [ 3313.874711][ T4013] ksys_read+0x78/0xe8 [ 3313.874714][ T4013] __arm64_sys_read+0x1c/0x2c [ 3313.874718][ T4013] invoke_syscall+0x58/0x114 [ 3313.874721][ T4013] el0_svc_common+0x80/0xe0 [ 3313.874724][ T4013] do_el0_svc+0x1c/0x28 [ 3313.874727][ T4013] el0_svc+0x38/0x68 [ 3313.874730][ T4013] el0t_64_sync_handler+0x68/0xbc [ 3313.874732][ T4013] el0t_64_sync+0x1a8/0x1ac Signed-off-by: Mukesh Ojha Reviewed-by: Anish Kumar Link: https://lore.kernel.org/r/20241103160527.82487-1-quic_mojha@quicinc.com Signed-off-by: Lee Jones

leds: Introduce ordered workqueue for LEDs events instead of system_wq

2024-11-06T08:11:19+00:00

This allows to setup ordered workqueue for LEDs events. This may be useful, because default 'system_wq' does not guarantee execution order of each work_struct, thus for several brightness update requests (for multiple LEDs), real brightness switch could be in random order. Yes, for sysfs-based LEDs we have flush_work() call inside brightness_store() operation, but it's blocking call, so userspace caller can be blocked at a long time, which means LEDs animation stream can be broken. Ordered workqueue has the same behaviour as system_wq + flush_work(), but all scheduled works are async and userspace caller is not blocked, which it better for userspace animation scheduling. Signed-off-by: Alexey Romanov Signed-off-by: Dmitry Rokosov Link: https://lore.kernel.org/r/20240903223936.21292-1-ddrokosov@salutedevices.com [Lee: Couple of style fix-ups] Signed-off-by: Lee Jones

Merge tag 'leds-next-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds

2024-07-18T00:51:30+00:00

Pull LED updates from Lee Jones: "Core Frameworks: - New trigger for Input Events - New led_mc_set_brightness() call to adapt colour/brightness for mutli-colour LEDs - New lled_mc_trigger_event() call to call the above based on given trigger conditions - New led_get_color_name() call, a wrapper around the existing led_colors[] array - A new flag to avoid automatic renaming of LED devices New Drivers: - Silergy SY7802 Flash LED Controller - Texas Instruments LP5569 LED Controller - ChromeOS EC LED Controller New Device Support: - KTD202{6,7} support for Kinetic KTD2026/7 LEDs Fix-ups: - Replace ACPI/DT firmware helpers with agnostic variants - Make use of resource managed devm_* API calls - Device Tree binding adaptions/conversions/creation - Constify/staticise applicable data structures - Trivial; spelling, whitespace, coding-style adaptions - Drop i2c_device_id::driver_data where the value is unused - Utilise centrally provided helpers and macros to aid simplicity and avoid duplication - Use generic platform device properties instead of OF/ACPI specific ones - Consolidate/de-duplicate various functionality - Remove superfluous/duplicated/unused sections - Make use of the new *_scoped() guard APIs - Improve/simplify error handling Bug Fixes: - Flush pending brightness changes before activating the trigger - Repair incorrect device naming preventing matches - Prevent memory leaks by correctly free resources during error handling routines - Repair locking issue causing circular dependency splats and lock-ups - Unregister sysfs entries before deactivating triggers to prevent use-after issues - Supply a bunch of MODULE_DESCRIPTIONs to silence modpost warnings - Use correct return codes expected by the callers - Omit set_brightness() error message for a LEDs that support only HW triggers" * tag 'leds-next-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds: (65 commits) leds: leds-lp5569: Enable chip after chip configuration leds: leds-lp5569: Better handle enabling clock internal setting leds: leds-lp5569: Fix typo in driver name leds: flash: leds-qcom-flash: Test the correct variable in init leds: leds-lp55xx: Convert mutex lock/unlock to guard API leds: leds-lp5523: Convert to sysfs_emit API leds: leds-lp5569: Convert to sysfs_emit API Revert "leds: led-core: Fix refcount leak in of_led_get()" leds: leds-lp5569: Add support for Texas Instruments LP5569 leds: leds-lp55xx: Drop deprecated defines leds: leds-lp55xx: Support ENGINE program up to 128 bytes leds: leds-lp55xx: Generalize sysfs master_fader leds: leds-lp55xx: Generalize sysfs engine_leds leds: leds-lp55xx: Generalize sysfs engine_load and engine_mode leds: leds-lp55xx: Generalize stop_engine function leds: leds-lp55xx: Generalize turn_off_channels function leds: leds-lp55xx: Generalize set_led_current function leds: leds-lp55xx: Generalize multicolor_brightness function leds: leds-lp55xx: Generalize led_brightness function leds: leds-lp55xx: Generalize firmware_loaded function ...

Merge tag 'mfd-next-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd

2024-07-18T00:42:20+00:00

Pull MFD updates from Lee Jones: "New Drivers: - ROHM BD96801 Power Management IC - Cirrus Logic CS40L50 Haptic Driver with Waveform Memory - Marvell 88PM886 Power Management IC New Device Support: - Keyboard Backlight to ChromeOS Embedded Controller - LEDs to ChromeOS Embedded Controller - Charge Control to ChromeOS Embedded Controller - HW Monitoring Service to ChromeOS Embedded Controller - AUXADCs to MediaTek MT635{7,8,9} Power Management ICs New Functionality: - Allow Syscon consumers to supply their own Regmaps on registration Fix-ups: - Constify/staticise applicable data structures - Remove superfluous/duplicated/unused sections - Device Tree binding adaptions/conversions/creation - Trivial; spelling, whitespace, coding-style adaptions - Utilise centrally provided helpers and macros to aid simplicity/duplication - Drop i2c_device_id::driver_data where the value is unused - Replace ACPI/DT firmware helpers with agnostic variants - Move over to GPIOD (descriptor-based) APIs - Annotate a bunch of __counted_by() cases - Straighten out some includes Bug Fixes: - Ensure potentially asserted recent lines are deasserted during initialisation - Avoid ".ko is added to multiple modules" warnings - Supply a bunch of MODULE_DESCRIPTIONs to silence modpost warnings - Fix Wvoid-pointer-to-enum-cast warnings" * tag 'mfd-next-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (87 commits) mfd: timberdale: Attach device properties to TSC2007 board info mfd: tmio: Move header to platform_data mfd: tmio: Sanitize comments mfd: tmio: Update include files mmc: tmio/sdhi: Fix includes mfd: tmio: Remove obsolete io accessors mfd: tmio: Remove obsolete platform_data watchdog: bd96801_wdt: Add missing include for FIELD_*() dt-bindings: mfd: syscon: Add APM poweroff mailbox dt-bindings: mfd: syscon: Split and enforce documenting MFD children dt-bindings: mfd: rk817: Merge support for RK809 dt-bindings: mfd: rk817: Fixup clocks and reference dai-common dt-bindings: mfd: syscon: Add TI's opp table compatible mfd: omap-usb-tll: Use struct_size to allocate tll dt-bindings: mfd: Explain lack of child dependency in simple-mfd dt-bindings: mfd: Dual licensing for st,stpmic1 bindings mfd: omap-usb-tll: Annotate struct usbtll_omap with __counted_by mfd: tps6594-core: Remove unneeded semicolon in tps6594_check_crc_mode() mfd: lm3533: Move to new GPIO descriptor-based APIs mfd: tps65912: Use devm helper functions to simplify probe ...