Commit a1bae672 authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
Browse files

[PATCH] i386: Disable nmi watchdog on all ThinkPads 



Even newer Thinkpads have bugs in SMM code that causes hangs with
NMI watchdog.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 581910e2

arch/i386/kernel/nmi.c

+5 −5
Original line number Diff line number Diff line
@@ -219,11 +219,11 @@ static int __init check_nmi_watchdog(void) 
	int cpu;



	/* Enable NMI watchdog for newer systems.

           Actually it should be safe for most systems before 2004 too except

	   for some IBM systems that corrupt registers when NMI happens

	   during SMM. Unfortunately we don't have more exact information

 	   on these and use this coarse check. */

	if (nmi_watchdog == NMI_DEFAULT && dmi_get_year(DMI_BIOS_DATE) >= 2004)

	   Probably safe on most older systems too, but let's be careful.

	   IBM ThinkPads use INT10 inside SMM and that allows early NMI inside SMM

	   which hangs the system. Disable watchdog for all thinkpads */

	if (nmi_watchdog == NMI_DEFAULT && dmi_get_year(DMI_BIOS_DATE) >= 2004 &&

		!dmi_name_in_vendors("ThinkPad"))

		nmi_watchdog = NMI_LOCAL_APIC;



	if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DEFAULT))

drivers/firmware/dmi_scan.c

+20 −0
Original line number Diff line number Diff line
@@ -326,6 +326,26 @@ char *dmi_get_system_info(int field) 
}

EXPORT_SYMBOL(dmi_get_system_info);





/**

 *	dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.

 *	@str: 	Case sensitive Name

 */

int dmi_name_in_vendors(char *str)

{

	static int fields[] = { DMI_BIOS_VENDOR, DMI_BIOS_VERSION, DMI_SYS_VENDOR,

				DMI_PRODUCT_NAME, DMI_PRODUCT_VERSION, DMI_BOARD_VENDOR,

				DMI_BOARD_NAME, DMI_BOARD_VERSION, DMI_NONE };

	int i;

	for (i = 0; fields[i] != DMI_NONE; i++) {

		int f = fields[i];

		if (dmi_ident[f] && strstr(dmi_ident[f], str))

			return 1;

	}

	return 0;

}

EXPORT_SYMBOL(dmi_name_in_vendors);



/**

 *	dmi_find_device - find onboard device by type/name

 *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types

include/linux/dmi.h

+2 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ extern struct dmi_device * dmi_find_device(int type, const char *name, 
	struct dmi_device *from);

extern void dmi_scan_machine(void);

extern int dmi_get_year(int field);

extern int dmi_name_in_vendors(char *str);



#else
@@ -77,6 +78,7 @@ static inline char * dmi_get_system_info(int field) { return NULL; } 
static inline struct dmi_device * dmi_find_device(int type, const char *name,

	struct dmi_device *from) { return NULL; }

static inline int dmi_get_year(int year) { return 0; }

static inline int dmi_name_in_vendors(char *s) { return 0; }



#endif