From 3f9e12e0df012c4a9a7fd7eb0d3ae69b459d6b2c Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 6 Feb 2020 16:58:45 +0100 Subject: ACPI: watchdog: Allow disabling WDAT at boot In case the WDAT interface is broken, give the user an option to ignore it to let a native driver bind to the watchdog device instead. Signed-off-by: Jean Delvare Acked-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki --- Documentation/admin-guide/kernel-parameters.txt | 4 ++++ drivers/acpi/acpi_watchdog.c | 12 +++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index dbc22d684627..c07815d230bc 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -136,6 +136,10 @@ dynamic table installation which will install SSDT tables to /sys/firmware/acpi/tables/dynamic. + acpi_no_watchdog [HW,ACPI,WDT] + Ignore the ACPI-based watchdog interface (WDAT) and let + a native driver control the watchdog device instead. + acpi_rsdp= [ACPI,EFI,KEXEC] Pass the RSDP address to the kernel, mostly used on machines running EFI runtime service to boot the diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c index b5516b04ffc0..ab6e434b4cee 100644 --- a/drivers/acpi/acpi_watchdog.c +++ b/drivers/acpi/acpi_watchdog.c @@ -55,12 +55,14 @@ static bool acpi_watchdog_uses_rtc(const struct acpi_table_wdat *wdat) } #endif +static bool acpi_no_watchdog; + static const struct acpi_table_wdat *acpi_watchdog_get_wdat(void) { const struct acpi_table_wdat *wdat = NULL; acpi_status status; - if (acpi_disabled) + if (acpi_disabled || acpi_no_watchdog) return NULL; status = acpi_get_table(ACPI_SIG_WDAT, 0, @@ -88,6 +90,14 @@ bool acpi_has_watchdog(void) } EXPORT_SYMBOL_GPL(acpi_has_watchdog); +/* ACPI watchdog can be disabled on boot command line */ +static int __init disable_acpi_watchdog(char *str) +{ + acpi_no_watchdog = true; + return 1; +} +__setup("acpi_no_watchdog", disable_acpi_watchdog); + void __init acpi_watchdog_init(void) { const struct acpi_wdat_entry *entries; -- cgit v1.2.3 From 1dade3a7048ccfc675650cd2cf13d578b095e5fb Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Wed, 12 Feb 2020 17:59:39 +0300 Subject: ACPICA: Introduce ACPI_ACCESS_BYTE_WIDTH() macro Sometimes it is useful to find the access_width field value in bytes and not in bits so add a helper that can be used for this purpose. Suggested-by: Jean Delvare Signed-off-by: Mika Westerberg Reviewed-by: Jean Delvare Cc: 4.16+ # 4.16+ Signed-off-by: Rafael J. Wysocki --- include/acpi/actypes.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index a2583c2bc054..4defed58ea33 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -532,11 +532,12 @@ typedef u64 acpi_integer; strnlen (a, ACPI_NAMESEG_SIZE) == ACPI_NAMESEG_SIZE) /* - * Algorithm to obtain access bit width. + * Algorithm to obtain access bit or byte width. * Can be used with access_width of struct acpi_generic_address and access_size of * struct acpi_resource_generic_register. */ #define ACPI_ACCESS_BIT_WIDTH(size) (1 << ((size) + 2)) +#define ACPI_ACCESS_BYTE_WIDTH(size) (1 << ((size) - 1)) /******************************************************************************* * -- cgit v1.2.3 From 2ba33a4e9e22ac4dda928d3e9b5978a3a2ded4e0 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Wed, 12 Feb 2020 17:59:40 +0300 Subject: ACPI: watchdog: Fix gas->access_width usage ACPI Generic Address Structure (GAS) access_width field is not in bytes as the driver seems to expect in few places so fix this by using the newly introduced macro ACPI_ACCESS_BYTE_WIDTH(). Fixes: b1abf6fc4982 ("ACPI / watchdog: Fix off-by-one error at resource assignment") Fixes: 058dfc767008 ("ACPI / watchdog: Add support for WDAT hardware watchdog") Reported-by: Jean Delvare Signed-off-by: Mika Westerberg Reviewed-by: Jean Delvare Cc: 4.16+ # 4.16+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_watchdog.c | 3 +-- drivers/watchdog/wdat_wdt.c | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c index ab6e434b4cee..6e9ec6e3fe47 100644 --- a/drivers/acpi/acpi_watchdog.c +++ b/drivers/acpi/acpi_watchdog.c @@ -136,12 +136,11 @@ void __init acpi_watchdog_init(void) gas = &entries[i].register_region; res.start = gas->address; + res.end = res.start + ACPI_ACCESS_BYTE_WIDTH(gas->access_width) - 1; if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { res.flags = IORESOURCE_MEM; - res.end = res.start + ALIGN(gas->access_width, 4) - 1; } else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { res.flags = IORESOURCE_IO; - res.end = res.start + gas->access_width - 1; } else { pr_warn("Unsupported address space: %u\n", gas->space_id); diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c index b069349b52f5..e1b1fcfc02af 100644 --- a/drivers/watchdog/wdat_wdt.c +++ b/drivers/watchdog/wdat_wdt.c @@ -389,7 +389,7 @@ static int wdat_wdt_probe(struct platform_device *pdev) memset(&r, 0, sizeof(r)); r.start = gas->address; - r.end = r.start + gas->access_width - 1; + r.end = r.start + ACPI_ACCESS_BYTE_WIDTH(gas->access_width) - 1; if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { r.flags = IORESOURCE_MEM; } else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { -- cgit v1.2.3 From cabe17d0173ab04bd3f87b8199ae75f43f1ea473 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Wed, 12 Feb 2020 17:59:41 +0300 Subject: ACPI: watchdog: Set default timeout in probe If the BIOS default timeout for the watchdog is too small userspace may not have enough time to configure new timeout after opening the device before the system is already reset. For this reason program default timeout of 30 seconds in the driver probe and allow userspace to change this from command line or through module parameter (wdat_wdt.timeout). Reported-by: Jean Delvare Signed-off-by: Mika Westerberg Reviewed-by: Jean Delvare Signed-off-by: Rafael J. Wysocki --- drivers/watchdog/wdat_wdt.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c index e1b1fcfc02af..3065dd670a18 100644 --- a/drivers/watchdog/wdat_wdt.c +++ b/drivers/watchdog/wdat_wdt.c @@ -54,6 +54,13 @@ module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +#define WDAT_DEFAULT_TIMEOUT 30 + +static int timeout = WDAT_DEFAULT_TIMEOUT; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=" + __MODULE_STRING(WDAT_DEFAULT_TIMEOUT) ")"); + static int wdat_wdt_read(struct wdat_wdt *wdat, const struct wdat_instruction *instr, u32 *value) { @@ -438,6 +445,22 @@ static int wdat_wdt_probe(struct platform_device *pdev) platform_set_drvdata(pdev, wdat); + /* + * Set initial timeout so that userspace has time to configure the + * watchdog properly after it has opened the device. In some cases + * the BIOS default is too short and causes immediate reboot. + */ + if (timeout * 1000 < wdat->wdd.min_hw_heartbeat_ms || + timeout * 1000 > wdat->wdd.max_hw_heartbeat_ms) { + dev_warn(dev, "Invalid timeout %d given, using %d\n", + timeout, WDAT_DEFAULT_TIMEOUT); + timeout = WDAT_DEFAULT_TIMEOUT; + } + + ret = wdat_wdt_set_timeout(&wdat->wdd, timeout); + if (ret) + return ret; + watchdog_set_nowayout(&wdat->wdd, nowayout); return devm_watchdog_register_device(dev, &wdat->wdd); } -- cgit v1.2.3