kernel/linux.git/drivers/watchdog, branch v6.18.40

watchdog: unregister PM notifier on watchdog unregister

2026-07-24T14:16:04+00:00

[ Upstream commit a298c7302ee9584a7a1ac1e8acbede8d98ab51a4 ] watchdog_register_device() registers wdd->pm_nb when WDOG_NO_PING_ON_SUSPEND is set, but watchdog_unregister_device() does not remove it. This leaves an embedded notifier block on the PM notifier chain after the watchdog device has been unregistered. A later suspend/resume notification can then call watchdog_pm_notifier() with a stale watchdog_device pointer, or at minimum after wdd->wd_data has been cleared by watchdog_dev_unregister(). Unregister the PM notifier before tearing down the watchdog device. Fixes: 60bcd91aafd2 ("watchdog: introduce watchdog_dev_suspend/resume") Signed-off-by: Yuho Choi Link: https://lore.kernel.org/r/20260601192005.1970805-1-dbgh9129@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: sprd_wdt: Remove redundant sprd_wdt_disable() on register failure

2026-07-24T14:15:45+00:00

[ Upstream commit 96b3cfc3b8ad0524d12fed1e08bc5df3ff345f64 ] The driver uses devm_add_action_or_reset() to register sprd_wdt_disable() as a managed cleanup action. When devm_watchdog_register_device() fails, the devm core will invoke the cleanup action automatically. The explicit sprd_wdt_disable() call in the error path is therefore redundant and results in adouble cleanup. Fixes: 78d9bfad2e89 ("watchdog: sprd_wdt: Convert to use device managed functions and other improvements") Signed-off-by: Felix Gu Reviewed-by: Guenter Roeck Reviewed-by: Baolin Wang Link: https://lore.kernel.org/r/20260223-sprd_wdt-v1-1-2e71f9a76ecb@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: sama5d4_wdt: Fix WDDIS detection on SAM9X60 and SAMA7G5

2026-07-24T14:15:45+00:00

[ Upstream commit e8bc610b14a99d24b0916635102cc52ba41def9b ] The driver hardcoded AT91_WDT_WDDIS (bit 15) in wdt_enabled and the probe initial state readout. SAM9X60 and SAMA7G5 use bit 12 (AT91_SAM9X60_WDDIS), causing incorrect WDDIS detection. Introduce a per-device wddis_mask field to select the correct WDDIS bit based on the compatible string. Fixes: 266da53c35fc ("watchdog: sama5d4: readout initial state") Co-developed-by: Andrei Simion Signed-off-by: Andrei Simion Signed-off-by: Balakrishnan Sambath Reviewed-by: Alexandre Belloni Link: https://lore.kernel.org/r/20260302113310.133989-2-balakrishnan.s@microchip.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: sp5100_tco: Use EFCH MMIO for newer Hygon FCH

2026-07-24T14:15:45+00:00

[ Upstream commit 4f675f036cd5e9cfbe6df5f24f8338158af96a4b ] Commit 009637de1f65 ("watchdog: sp5100_tco: support Hygon FCH/SCH (Server Controller Hub)") added Hygon vendor matching to the efch layout selection, but newer Hygon 0x790b SMBus devices still need the efch_mmio path. The efch_mmio path enables EFCH_PM_DECODEEN_WDT_TMREN before probing the watchdog MMIO block. If firmware leaves that bit clear and the driver picks the legacy efch path instead, probe falls back to the alternate window and fails with "Watchdog hardware is disabled". Select efch_mmio for Hygon 0x790b devices with revision 0x51 or later, matching the equivalent AMD behavior and allowing the watchdog to initialize on those systems. Fixes: 009637de1f65 ("watchdog: sp5100_tco: support Hygon FCH/SCH (Server Controller Hub)") Signed-off-by: Yingjie Gao Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20260402071617.634563-2-gaoyingjie@uniontech.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: apple: Add "apple,t8103-wdt" compatible

2026-07-18T14:53:30+00:00

commit 14ca4868886f2188401fe06cd7bf01a330b3fb99 upstream. After discussion with the devicetree maintainers we agreed to not extend lists with the generic compatible "apple,wdt" anymore [1]. Use "apple,t8103-wdt" as base compatible as it is the SoC the driver and bindings were written for. [1]: https://lore.kernel.org/asahi/12ab93b7-1fc2-4ce0-926e-c8141cfe81bf@kernel.org/ Fixes: 4ed224aeaf66 ("watchdog: Add Apple SoC watchdog driver") Cc: stable@vger.kernel.org Reviewed-by: Neal Gompa Signed-off-by: Janne Grunau Link: https://lore.kernel.org/r/20251231-watchdog-apple-t8103-base-compat-v1-1-1702a02e0c45@jannau.net Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

watchdog: rzv2h_wdt: Discard pm_runtime_put() return value

2026-03-04T12:20:36+00:00

[ Upstream commit 2dea984a74265a67e3210f818416a83b87f70200 ] Failing device probe due to pm_runtime_put() returning an error is not particularly useful. Returning an error code from pm_runtime_put() merely means that it has not queued up a work item to check whether or not the device can be suspended and there are many perfectly valid situations in which that can happen, like after writing "on" to the devices' runtime PM "control" attribute in sysfs for one example. It also happens when the kernel is configured with CONFIG_PM unset. Accordingly, update rzt2h_wdt_wdtdcr_init() to simply discard the return value of pm_runtime_put() and return success to the caller after invoking that function. This will facilitate a planned change of the pm_runtime_put() return type to void in the future. Signed-off-by: Rafael J. Wysocki Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin

watchdog: imx7ulp_wdt: handle the nowayout option

2026-03-04T12:20:36+00:00

[ Upstream commit d303d37ef5cf86c8c3b2daefd2a7d7fd8ca1ec14 ] The module parameter `nowayout` indicates whether the watchdog should ever be allowed to stop, but the driver currently ignores this option. Pass the `nowayout` parameter to the watchdog core by setting the WDOG_NO_WAY_OUT flag accordingly. Signed-off-by: Oleksandr Suvorov Reviewed-by: Guenter Roeck Reviewed-by: Frank Li Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin

fix it87_wdt early reboot by reporting running timer

2026-03-04T12:20:35+00:00

[ Upstream commit 88b2ab346436f799b99894a3e9518a3ffa344524 ] Some products, such as the Ugreen DXP4800 Plus NAS, ship with the it87 wdt enabled by the firmware and a broken BIOS option that does not allow to change the time or turn it off. As this makes installing Linux rather difficult, change the it87_wdt to report it running to the watchdog core. Signed-off-by: René Rebe Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin

watchdog: starfive-wdt: Fix PM reference leak in probe error path

2026-02-26T22:59:34+00:00

[ Upstream commit 3f2d8d79cceb05a8b8dd200fa81c0dffc59ec46f ] The PM reference count is not expected to be incremented on return in functions starfive_wdt_probe. However, pm_runtime_get_sync will increment pm usage counter even failed. Forgetting to putting operation will result in a reference leak here. Replace it with pm_runtime_resume_and_get to keep usage counter balanced. Fixes: db728ea9c7be ("drivers: watchdog: Add StarFive Watchdog driver") Signed-off-by: Kery Qi Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin

via_wdt: fix critical boot hang due to unnamed resource allocation

2026-01-02T11:57:01+00:00

[ Upstream commit 7aa31ee9ec92915926e74731378c009c9cc04928 ] The VIA watchdog driver uses allocate_resource() to reserve a MMIO region for the watchdog control register. However, the allocated resource was not given a name, which causes the kernel resource tree to contain an entry marked as "" under /proc/iomem on x86 platforms. During boot, this unnamed resource can lead to a critical hang because subsequent resource lookups and conflict checks fail to handle the invalid entry properly. Signed-off-by: Li Qiang Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin