diff options
| -rw-r--r-- | drivers/watchdog/iTCO_vendor_support.c | 82 |
1 files changed, 76 insertions, 6 deletions
diff --git a/drivers/watchdog/iTCO_vendor_support.c b/drivers/watchdog/iTCO_vendor_support.c index 843ef62..5133bca 100644 --- a/drivers/watchdog/iTCO_vendor_support.c +++ b/drivers/watchdog/iTCO_vendor_support.c @@ -19,7 +19,7 @@ /* Module and version information */ #define DRV_NAME "iTCO_vendor_support" -#define DRV_VERSION "1.03" +#define DRV_VERSION "1.04" #define PFX DRV_NAME ": " /* Includes */ @@ -44,11 +44,14 @@ #define SUPERMICRO_OLD_BOARD 1 /* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems */ #define SUPERMICRO_NEW_BOARD 2 +/* Broken BIOS */ +#define BROKEN_BIOS 911 static int vendorsupport; module_param(vendorsupport, int, 0); MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default=" - "0 (none), 1=SuperMicro Pent3, 2=SuperMicro Pent4+"); + "0 (none), 1=SuperMicro Pent3, 2=SuperMicro Pent4+, " + "911=Broken SMI BIOS"); /* * Vendor Specific Support @@ -243,25 +246,92 @@ static void supermicro_new_pre_set_heartbeat(unsigned int heartbeat) } /* + * Vendor Support: 911 + * Board: Some Intel ICHx based motherboards + * iTCO chipset: ICH7+ + * + * Some Intel motherboards have a broken BIOS implementation: i.e. + * the SMI handler clear's the TIMEOUT bit in the TC01_STS register + * and does not reload the time. Thus the TCO watchdog does not reboot + * the system. + * + * These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after + * debugging: the SMI handler is quite simple - it tests value in + * TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set + * the handler goes into an infinite loop, apparently to allow the + * second timeout and reboot. Otherwise it simply clears TIMEOUT bit + * in TCO1_STS and that's it. + * So the logic seems to be reversed, because it is hard to see how + * TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set + * (other than a transitional effect). + * + * The only fix found to get the motherboard(s) to reboot is to put + * the glb_smi_en bit to 0. This is a dirty hack that bypasses the + * broken code by disabling Global SMI. + * + * WARNING: globally disabling SMI could possibly lead to dramatic + * problems, especially on laptops! I.e. various ACPI things where + * SMI is used for communication between OS and firmware. + * + * Don't use this fix if you don't need to!!! + */ + +static void broken_bios_start(unsigned long acpibase) +{ + unsigned long val32; + + val32 = inl(SMI_EN); + /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# + Bit 0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */ + val32 &= 0xffffdffe; + outl(val32, SMI_EN); +} + +static void broken_bios_stop(unsigned long acpibase) +{ + unsigned long val32; + + val32 = inl(SMI_EN); + /* Bit 13: TCO_EN -> 1 = Enables TCO logic generating an SMI# + Bit 0: GBL_SMI_EN -> 1 = Turn global SMI on again. */ + val32 |= 0x00002001; + outl(val32, SMI_EN); +} + +/* * Generic Support Functions */ void iTCO_vendor_pre_start(unsigned long acpibase, unsigned int heartbeat) { - if (vendorsupport == SUPERMICRO_OLD_BOARD) + switch (vendorsupport) { + case SUPERMICRO_OLD_BOARD: supermicro_old_pre_start(acpibase); - else if (vendorsupport == SUPERMICRO_NEW_BOARD) + break; + case SUPERMICRO_NEW_BOARD: supermicro_new_pre_start(heartbeat); + break; + case BROKEN_BIOS: + broken_bios_start(acpibase); + break; + } } EXPORT_SYMBOL(iTCO_vendor_pre_start); void iTCO_vendor_pre_stop(unsigned long acpibase) { - if (vendorsupport == SUPERMICRO_OLD_BOARD) + switch (vendorsupport) { + case SUPERMICRO_OLD_BOARD: supermicro_old_pre_stop(acpibase); - else if (vendorsupport == SUPERMICRO_NEW_BOARD) + break; + case SUPERMICRO_NEW_BOARD: supermicro_new_pre_stop(); + break; + case BROKEN_BIOS: + broken_bios_stop(acpibase); + break; + } } EXPORT_SYMBOL(iTCO_vendor_pre_stop); |