From eaa7571b2d1a08873e4bdd8e6db3431df61cd9ad Mon Sep 17 00:00:00 2001 From: Henrique de Moraes Holschuh Date: Tue, 24 Apr 2007 11:48:18 -0300 Subject: ACPI: thinkpad-acpi: add a safety net for TPEC fan control mode The Linux ThinkPad community is not positive that all ThinkPads that do HFSP EC fan control do implement full-speed and auto modes, some of the earlier ones supporting HFSP might not. If the EC ignores the AUTO or FULL-SPEED bits, it will pay attention to the lower three bits that set the fan level. And as thinkpad-acpi was leaving these set to zero, it would stop(!) the fan, which is Not A Good Thing. So, as a safety net, we now make sure to also set the fan level part of the HFSP register to speed 7 for full-speed, and a minimum of speed 4 for auto mode. Signed-off-by: Henrique de Moraes Holschuh Signed-off-by: Len Brown --- drivers/misc/thinkpad_acpi.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c index a4d7ee47239..79abc6841e3 100644 --- a/drivers/misc/thinkpad_acpi.c +++ b/drivers/misc/thinkpad_acpi.c @@ -3185,6 +3185,13 @@ static int fan_set_level(int level) ((level < 0) || (level > 7))) return -EINVAL; + /* safety net should the EC not support AUTO + * or FULLSPEED mode bits and just ignore them */ + if (level & TP_EC_FAN_FULLSPEED) + level |= 7; /* safety min speed 7 */ + else if (level & TP_EC_FAN_FULLSPEED) + level |= 4; /* safety min speed 4 */ + if (!acpi_ec_write(fan_status_offset, level)) return -EIO; else @@ -3233,8 +3240,10 @@ static int fan_set_enable(void) break; /* Don't go out of emergency fan mode */ - if (s != 7) - s = TP_EC_FAN_AUTO; + if (s != 7) { + s &= 0x07; + s |= TP_EC_FAN_AUTO | 4; /* min fan speed 4 */ + } if (!acpi_ec_write(fan_status_offset, s)) rc = -EIO; @@ -3252,8 +3261,7 @@ static int fan_set_enable(void) s &= 0x07; /* Set fan to at least level 4 */ - if (s < 4) - s = 4; + s |= 4; if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", s)) rc= -EIO; -- cgit v1.2.3-70-g09d2