Date: Fri, 10 Oct 2008 15:31:20 +0200 From: Patrick =?ISO-8859-15?Q?Lamaizi=E8re?= <patfbsd@davenulle.org> To: FreeBSD Current <freebsd-current@freebsd.org> Subject: watchdog(9) bug in geode cs5536 watchdog Message-ID: <20081010153120.2ca88ef5@baby-jane-lamaiziere-net.local>
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[-- Attachment #1 --] Hello, On a soekris Net5501, if you do a watchdog -t 16, followed by a watchdog -t 0 to disable the watchdog, and then after some time (16s) re-enable the watchdog the box reboots immediatly. This prevents also to stop and restart watchdogd(8). This is because when you stop the watchdog, the timer is not stoped, only the hard reset is disabled. So when the timer has elapsed, the C2 event of the timer is set. But when the hard reset is re-enabled, the event is not cleared and the box reboots. The attached patch stops and resets the counter when the watchdog is disabled and do not disable the hard reset of the timer (if the timer has elapsed it's too late). (also on http://user.lamaiziere.net/patrick/geode.c-patch.txt) Regards. [-- Attachment #2 --] --- geode.c 2008-10-09 20:52:47.000000000 +0200 +++ /usr/src/sys/i386/i386/geode.c 2008-10-10 10:25:47.000000000 +0200 @@ -208,14 +208,11 @@ static void cs5536_watchdog(void *foo __unused, u_int cmd, int *error) { - u_int u, p; + u_int u, p, s; uint16_t a; uint32_t m; a = rdmsr(0x5140000d); - m = rdmsr(0x51400029); - m &= ~(1 << 24); - wrmsr(0x51400029, m); u = cmd & WD_INTERVAL; if (u >= 30 && u <= 44) { @@ -228,12 +225,24 @@ /* reset counter */ outw(a + 4, 0); /* Arm reset mechanism */ + m = rdmsr(0x51400029); m |= (1 << 24); wrmsr(0x51400029, m); /* Start counter */ outw(a + 6, 0x8000); *error = 0; + } else { + /* + * MFGPT_SETUP is write-once + * Check if the counter has been setup + */ + s = inw(a + 6); + if (s & (1 << 12)) { + /* Stop and reset counter */ + outw(a + 6, 0); + outw(a + 4, 0); + } } }
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