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authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>2007-04-24 11:48:18 -0300
committerLen Brown <len.brown@intel.com>2007-04-25 02:00:27 -0400
commiteaa7571b2d1a08873e4bdd8e6db3431df61cd9ad (patch)
treec1da58f58809ebc91afa1133a4e42e0dbe8acb48 /drivers/misc/thinkpad_acpi.c
parentfe98a52ce7540fb3a19d57488a08864110cf4d5c (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>
Diffstat (limited to 'drivers/misc/thinkpad_acpi.c')
-rw-r--r--drivers/misc/thinkpad_acpi.c16
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;