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From: Jerry Hoemann <jerry.hoemann@hpe.com>
To: wim@linux-watchdog.org, linux@roeck-us.net
Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
	rwright@hpe.com, maurice.a.saldivar@hpe.com, mingo@kernel.org,
	marcus.folkesson@gmail.com, Jerry Hoemann <jerry.hoemann@hpe.com>
Subject: [PATCH v5 6/9] watchdog/hpwdt: remove allow_kdump module parameter.
Date: Sun, 25 Feb 2018 20:22:24 -0700	[thread overview]
Message-ID: <20180226032227.14615-7-jerry.hoemann@hpe.com> (raw)
In-Reply-To: <20180226032227.14615-1-jerry.hoemann@hpe.com>

The intent of this parameter is unclear and it sets up a
race between the reset of the system by ASR and crashdump.

The length of time between receipt of the pretimeout NMI
and the ASR reset of the system is fixed by hardware.

Turning the parameter off doesn't necessairly prevent a crash dump.
Also, having the ASR reset occur while the system is crash dumping
doesn't imply that the dump was hung given the short duration
between the NMI and the reset.

This parameter is not a substitute for having a architected watchdog
crashdump hang detection paridigm.

Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
---
 drivers/watchdog/hpwdt.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index 171d5033d7b5..68e84a212d00 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -36,9 +36,6 @@ static bool ilo5;
 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
 static unsigned int reload;			/* the computed soft_margin */
 static bool nowayout = WATCHDOG_NOWAYOUT;
-#ifdef CONFIG_HPWDT_NMI_DECODING
-static unsigned int allow_kdump = 1;
-#endif
 
 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
 static unsigned long __iomem *hpwdt_nmistat;
@@ -124,8 +121,7 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
 	if (ilo5 && ulReason == NMI_UNKNOWN && mynmi)
 		return NMI_DONE;
 
-	if (allow_kdump)
-		hpwdt_stop();
+	hpwdt_stop();
 
 	hex_byte_pack(panic_msg, mynmi);
 	nmi_panic(regs, panic_msg);
@@ -186,9 +182,8 @@ static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 		goto error2;
 
 	dev_info(&dev->dev,
-			"HPE Watchdog Timer Driver: NMI decoding initialized"
-			", allow kernel dump: %s (default = 1/ON)\n",
-			(allow_kdump == 0) ? "OFF" : "ON");
+		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
+
 	return 0;
 
 error2:
@@ -322,9 +317,4 @@ module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
-#ifdef CONFIG_HPWDT_NMI_DECODING
-module_param(allow_kdump, int, 0);
-MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
-#endif /* CONFIG_HPWDT_NMI_DECODING */
-
 module_pci_driver(hpwdt_driver);
-- 
2.13.6


  parent reply	other threads:[~2018-02-26  3:22 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-26  3:22 [PATCH v5 0/9] watchdog/hpwdt: Update driver to use watchdog core Jerry Hoemann
2018-02-26  3:22 ` [PATCH v5 1/9] watchdog/hpwdt: Update Module info and copyright Jerry Hoemann
2018-02-26  3:22 ` [PATCH v5 2/9] watchdog/hpwdt: Remove legacy NMI sourcing Jerry Hoemann
2018-02-26 14:11   ` Arnd Bergmann
2018-02-26 14:32     ` Guenter Roeck
2018-02-27  1:02       ` Jerry Hoemann
2018-02-27  1:29         ` Guenter Roeck
2018-02-28 19:45           ` Jerry Hoemann
2018-03-02  4:42             ` Guenter Roeck
2018-02-26  3:22 ` [PATCH v5 3/9] watchdog/hpwdt: Update nmi_panic message Jerry Hoemann
2018-02-26  3:22 ` [PATCH v5 4/9] watchdog/hpwdt: Modify to use watchdog core Jerry Hoemann
2018-02-26  3:22 ` [PATCH v5 5/9] watchdog/hpwdt: condition early return of NMI handler on iLO5 Jerry Hoemann
2018-02-26  3:22 ` Jerry Hoemann [this message]
2018-02-26  3:22 ` [PATCH v5 7/9] watchdog/hpwdt: Programable Pretimeout NMI Jerry Hoemann
2018-02-26  3:22 ` [PATCH v5 8/9] watchdog/hpwdt: Add dynamic debug Jerry Hoemann
2018-02-26  3:22 ` [PATCH v5 9/9] watchdog/hpwdt: Update driver version Jerry Hoemann
2018-03-02  4:42 ` [PATCH v5 0/9] watchdog/hpwdt: Update driver to use watchdog core Guenter Roeck

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