diff options
Diffstat (limited to 'drivers/acpi/acpi_watchdog.c')
| -rw-r--r-- | drivers/acpi/acpi_watchdog.c | 72 |
1 files changed, 45 insertions, 27 deletions
diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c index 4bde16fb97d8..95600309ce42 100644 --- a/drivers/acpi/acpi_watchdog.c +++ b/drivers/acpi/acpi_watchdog.c @@ -12,35 +12,51 @@ #define pr_fmt(fmt) "ACPI: watchdog: " fmt #include <linux/acpi.h> -#include <linux/dmi.h> #include <linux/ioport.h> #include <linux/platform_device.h> #include "internal.h" -static const struct dmi_system_id acpi_watchdog_skip[] = { - { - /* - * On Lenovo Z50-70 there are two issues with the WDAT - * table. First some of the instructions use RTC SRAM - * to store persistent information. This does not work well - * with Linux RTC driver. Second, more important thing is - * that the instructions do not actually reset the system. - * - * On this particular system iTCO_wdt seems to work just - * fine so we prefer that over WDAT for now. - * - * See also https://bugzilla.kernel.org/show_bug.cgi?id=199033. - */ - .ident = "Lenovo Z50-70", - .matches = { - DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), - DMI_MATCH(DMI_PRODUCT_NAME, "20354"), - DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo Z50-70"), - }, - }, - {} -}; +#ifdef CONFIG_RTC_MC146818_LIB +#include <linux/mc146818rtc.h> + +/* + * There are several systems where the WDAT table is accessing RTC SRAM to + * store persistent information. This does not work well with the Linux RTC + * driver so on those systems we skip WDAT driver and prefer iTCO_wdt + * instead. + * + * See also https://bugzilla.kernel.org/show_bug.cgi?id=199033. + */ +static bool acpi_watchdog_uses_rtc(const struct acpi_table_wdat *wdat) +{ + const struct acpi_wdat_entry *entries; + int i; + + entries = (struct acpi_wdat_entry *)(wdat + 1); + for (i = 0; i < wdat->entries; i++) { + const struct acpi_generic_address *gas; + + gas = &entries[i].register_region; + if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { + switch (gas->address) { + case RTC_PORT(0): + case RTC_PORT(1): + case RTC_PORT(2): + case RTC_PORT(3): + return true; + } + } + } + + return false; +} +#else +static bool acpi_watchdog_uses_rtc(const struct acpi_table_wdat *wdat) +{ + return false; +} +#endif static const struct acpi_table_wdat *acpi_watchdog_get_wdat(void) { @@ -50,9 +66,6 @@ static const struct acpi_table_wdat *acpi_watchdog_get_wdat(void) if (acpi_disabled) return NULL; - if (dmi_check_system(acpi_watchdog_skip)) - return NULL; - status = acpi_get_table(ACPI_SIG_WDAT, 0, (struct acpi_table_header **)&wdat); if (ACPI_FAILURE(status)) { @@ -60,6 +73,11 @@ static const struct acpi_table_wdat *acpi_watchdog_get_wdat(void) return NULL; } + if (acpi_watchdog_uses_rtc(wdat)) { + pr_info("Skipping WDAT on this system because it uses RTC SRAM\n"); + return NULL; + } + return wdat; } |