From: Marc van der Wal <x0r+ker...@x0r.fr> On some hardware platforms, the it87_wdt watchdog resets the machine despite the watchdog daemon running and writing to /dev/watchdog.
This is due to Consumer IR buffer underrun interrupts being used as triggers to reset the timer. On some buggy hardware implementations such as the iEi AFL-12A-N270 single-board computer, this method does not work. However, resetting the timer by writing its original timeout value in its configuration register over and over again suppresses the unwanted reboots. Add a module option (nocir), 0 by default in order not to break existing setups. Setting it to 1 enables the workaround. Fixes bug #42801 <https://bugzilla.kernel.org/show_bug.cgi?id=42801>. Tested primarily on Linux 3.5.7, applies cleanly on Linux 3.13.5. Signed-off-by: Marc van der Wal <x0r+ker...@x0r.fr> --- diff -rupN -X linux-3.13.5.orig/Documentation/dontdiff linux-3.13.5.orig/Documentation/watchdog/watchdog-parameters.txt linux-3.13.5/Documentation/watchdog/watchdog-parameters.txt --- linux-3.13.5.orig/Documentation/watchdog/watchdog-parameters.txt 2014-02-22 22:35:30.000000000 +0100 +++ linux-3.13.5/Documentation/watchdog/watchdog-parameters.txt 2014-03-06 09:51:36.330134802 +0100 @@ -150,6 +150,8 @@ nowayout: Disable watchdog shutdown on c ------------------------------------------------- it87_wdt: nogameport: Forbid the activation of game port, default=0 +nocir: Forbid the use of CIR (workaround for some buggy setups); set to 1 if +system resets despite watchdog daemon running, default=0 exclusive: Watchdog exclusive device open, default=1 timeout: Watchdog timeout in seconds, default=60 testmode: Watchdog test mode (1 = no reboot), default=0 diff -rupN -X linux-3.13.5.orig/Documentation/dontdiff linux-3.13.5.orig/drivers/watchdog/it87_wdt.c linux-3.13.5/drivers/watchdog/it87_wdt.c --- linux-3.13.5.orig/drivers/watchdog/it87_wdt.c 2014-02-22 22:35:30.000000000 +0100 +++ linux-3.13.5/drivers/watchdog/it87_wdt.c 2014-03-06 10:17:34.429991556 +0100 @@ -54,6 +54,7 @@ /* Defaults for Module Parameter */ #define DEFAULT_NOGAMEPORT 0 +#define DEFAULT_NOCIR 0 #define DEFAULT_EXCLUSIVE 1 #define DEFAULT_TIMEOUT 60 #define DEFAULT_TESTMODE 0 @@ -136,11 +137,13 @@ #define WDTS_LOCKED 3 #define WDTS_USE_GP 4 #define WDTS_EXPECTED 5 +#define WDTS_USE_CIR 6 static unsigned int base, gpact, ciract, max_units, chip_type; static unsigned long wdt_status; static int nogameport = DEFAULT_NOGAMEPORT; +static int nocir = DEFAULT_NOCIR; static int exclusive = DEFAULT_EXCLUSIVE; static int timeout = DEFAULT_TIMEOUT; static int testmode = DEFAULT_TESTMODE; @@ -149,6 +152,9 @@ static bool nowayout = DEFAULT_NOWAYOU module_param(nogameport, int, 0); MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default=" __MODULE_STRING(DEFAULT_NOGAMEPORT)); +module_param(nocir, int, 0); +MODULE_PARM_DESC(nocir, "Forbid the use of Consumer IR interrupts to reset timer, default=" + __MODULE_STRING(DEFAULT_NOCIR)); module_param(exclusive, int, 0); MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default=" __MODULE_STRING(DEFAULT_EXCLUSIVE)); @@ -258,9 +264,17 @@ static void wdt_keepalive(void) { if (test_bit(WDTS_USE_GP, &wdt_status)) inb(base); - else + else if (test_bit(WDTS_USE_CIR, &wdt_status)) /* The timer reloads with around 5 msec delay */ outb(0x55, CIR_DR(base)); + else { + if (superio_enter()) + return; + + superio_select(GPIO); + wdt_update_timeout(); + superio_exit(); + } set_bit(WDTS_KEEPALIVE, &wdt_status); } @@ -273,7 +287,7 @@ static int wdt_start(void) superio_select(GPIO); if (test_bit(WDTS_USE_GP, &wdt_status)) superio_outb(WDT_GAMEPORT, WDTCTRL); - else + else if (test_bit(WDTS_USE_CIR, &wdt_status)) superio_outb(WDT_CIRINT, WDTCTRL); wdt_update_timeout(); @@ -660,7 +674,7 @@ static int __init it87_wdt_init(void) } /* If we haven't Gameport support, try to get CIR support */ - if (!test_bit(WDTS_USE_GP, &wdt_status)) { + if (!nocir && !test_bit(WDTS_USE_GP, &wdt_status)) { if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) { if (gp_rreq_fail) pr_err("I/O Address 0x%04x and 0x%04x already in use\n", @@ -682,6 +696,7 @@ static int __init it87_wdt_init(void) superio_select(GAMEPORT); superio_outb(gpact, ACTREG); } + set_bit(WDTS_USE_CIR, &wdt_status); } if (timeout < 1 || timeout > max_units * 60) { @@ -707,7 +722,7 @@ static int __init it87_wdt_init(void) } /* Initialize CIR to use it as keepalive source */ - if (!test_bit(WDTS_USE_GP, &wdt_status)) { + if (test_bit(WDTS_USE_CIR, &wdt_status)) { outb(0x00, CIR_RCR(base)); outb(0xc0, CIR_TCR1(base)); outb(0x5c, CIR_TCR2(base)); @@ -717,9 +732,9 @@ static int __init it87_wdt_init(void) outb(0x09, CIR_IER(base)); } - pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d)\n", + pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d nocir=%d)\n", chip_type, chip_rev, timeout, - nowayout, testmode, exclusive, nogameport); + nowayout, testmode, exclusive, nogameport, nocir); superio_exit(); return 0; @@ -727,8 +742,10 @@ static int __init it87_wdt_init(void) err_out_reboot: unregister_reboot_notifier(&wdt_notifier); err_out_region: - release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8); - if (!test_bit(WDTS_USE_GP, &wdt_status)) { + if (test_bit(WDTS_USE_GP, &wdt_status)) + release_region(base, 1); + else if (test_bit(WDTS_USE_CIR, &wdt_status)) { + release_region(base, 8); superio_select(CIR); superio_outb(ciract, ACTREG); } @@ -754,7 +771,7 @@ static void __exit it87_wdt_exit(void) if (test_bit(WDTS_USE_GP, &wdt_status)) { superio_select(GAMEPORT); superio_outb(gpact, ACTREG); - } else { + } else if (test_bit(WDTS_USE_CIR, &wdt_status)) { superio_select(CIR); superio_outb(ciract, ACTREG); } @@ -763,7 +780,11 @@ static void __exit it87_wdt_exit(void) misc_deregister(&wdt_miscdev); unregister_reboot_notifier(&wdt_notifier); - release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8); + + if (test_bit(WDTS_USE_GP, &wdt_status)) + release_region(base, 1); + else if (test_bit(WDTS_USE_CIR, &wdt_status)) + release_region(base, 8); } module_init(it87_wdt_init); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
