diff options
| author | Henrique de Moraes Holschuh <hmh@hmh.eng.br> | 2007-04-24 11:48:18 -0300 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2007-04-25 02:00:27 -0400 |
| commit | eaa7571b2d1a08873e4bdd8e6db3431df61cd9ad (patch) | |
| tree | c1da58f58809ebc91afa1133a4e42e0dbe8acb48 | |
| parent | fe98a52ce7540fb3a19d57488a08864110cf4d5c (diff) | |
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 <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
| -rw-r--r-- | drivers/misc/thinkpad_acpi.c | 16 |
1 files changed, 12 insertions, 4 deletions
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; |