diff options
Diffstat (limited to '0003-ACPI-watchdog-Prefer-iTCO_wdt-always-when-WDAT-table.patch')
| -rw-r--r-- | 0003-ACPI-watchdog-Prefer-iTCO_wdt-always-when-WDAT-table.patch | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/0003-ACPI-watchdog-Prefer-iTCO_wdt-always-when-WDAT-table.patch b/0003-ACPI-watchdog-Prefer-iTCO_wdt-always-when-WDAT-table.patch new file mode 100644 index 000000000000..5c029d37f3ef --- /dev/null +++ b/0003-ACPI-watchdog-Prefer-iTCO_wdt-always-when-WDAT-table.patch @@ -0,0 +1,127 @@ +From 7bb20c91fc051b79bcd774030b6c900c29e325d4 Mon Sep 17 00:00:00 2001 +From: Mika Westerberg <mika.westerberg@linux.intel.com> +Date: Tue, 22 May 2018 14:16:50 +0300 +Subject: [PATCH 3/5] ACPI / watchdog: Prefer iTCO_wdt always when WDAT table + uses RTC SRAM + +After we added quirk for Lenovo Z50-70 it turns out there are at least +two more systems where WDAT table includes instructions accessing RTC +SRAM. Instead of quirking each system separately, look for such +instructions in the table and automatically prefer iTCO_wdt if found. + +Link: https://bugzilla.kernel.org/show_bug.cgi?id=199033 +Reported-by: Arnold Guy <aurnoldg@gmail.com> +Reported-by: Alois Nespor <nespor@fssp.cz> +Reported-by: Yury Pakin <zxwarior@gmail.com> +Reported-by: Ihor Chyhin <ihorchyhin@ukr.net> +Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> +Acked-by: Guenter Roeck <linux@roeck-us.net> +--- + drivers/acpi/acpi_watchdog.c | 72 ++++++++++++++++++++++-------------- + 1 file 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; + } + +-- +2.18.0 + |