watchdog: wdat_wdt: map registers that fall inside ACPI NVS

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Some firmwares describe WDAT registers inside memory ranges marked as
ACPI NVS in the E820 map, failing with -EBUSY during probe, leaving the
hardware watchdog unserviced and triggering periodic system resets.

This issue was observed on a OnLogic Karbon 524 device (when watchdog is
enabled in BIOS):

wdat_wdt wdat_wdt: error -EBUSY: can't request region for resource [mem 0x63df7a98]
wdat_wdt wdat_wdt: probe with driver wdat_wdt failed with error -16

Check whether the region falls inside ACPI NVS before requesting it and,
if so, map it without reservation.

Signed-off-by: Renê de Souza Pinto <rene@renesp.com.br>
Link: https://lore.kernel.org/r/20260804103958.3684195-1-rene@renesp.com.br
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

...

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Renê de Souza Pinto 2026-08-04 12:39:57 +02:00 • committed by Guenter Roeck

parent 80141041bd

commit 0ab46a83fa

1 changed files with 26 additions and 1 deletions

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drivers/watchdog/wdat_wdt.c

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