[ltp] [patch 09/12][2.6.18] ibm-acpi: fix and extend fan control functions
Henrique de Moraes Holschuh
linux-thinkpad@linux-thinkpad.org
Mon, 23 Oct 2006 12:17:54 -0300
This patch extend fan control functions, implementing enable/disable for
all write access modes, implementing level control for all level-capable
write access modes.
The patch also updates the documentation, explaining levels auto and
disengaged.
ABI changes:
1. Support level 0 as an equivalent to disable
2. Add support for level auto and level disengaged when doing
EC 0x2f fan control
3. Support enable/disable for all level-based write access modes
4. Add support for level command on FANS thinkpads, as per
thinkwiki reports
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: borislav@users.sourceforge.net
---
Documentation/ibm-acpi.txt | 66 ++++++++++++++++++++++++++++++++-------------
drivers/acpi/ibm_acpi.c | 57 +++++++++++++++++++++++++++++++++-----
2 files changed, 96 insertions(+), 27 deletions(-)
Index: 2.6.18/drivers/acpi/ibm_acpi.c
===================================================================
--- 2.6.18.orig/drivers/acpi/ibm_acpi.c
+++ 2.6.18/drivers/acpi/ibm_acpi.c
@@ -1766,7 +1766,8 @@ static int fan_init(void)
if (sfan_handle) {
/* 570, 770x-JL */
fan_control_access_mode = IBMACPI_FAN_WR_ACPI_SFAN;
- fan_control_commands |= IBMACPI_FAN_CMD_LEVEL;
+ fan_control_commands |= IBMACPI_FAN_CMD_LEVEL
+ | IBMACPI_FAN_CMD_ENABLE;
} else {
if (!gfan_handle) {
/* gfan without sfan means no fan control */
@@ -1775,10 +1776,13 @@ static int fan_init(void)
if (fans_handle) {
/* X31, X40, X41 */
fan_control_access_mode = IBMACPI_FAN_WR_ACPI_FANS;
- fan_control_commands |= IBMACPI_FAN_CMD_SPEED | IBMACPI_FAN_CMD_ENABLE;
+ fan_control_commands |= IBMACPI_FAN_CMD_SPEED
+ | IBMACPI_FAN_CMD_LEVEL
+ | IBMACPI_FAN_CMD_ENABLE;
} else {
fan_control_access_mode = IBMACPI_FAN_WR_TPEC;
- fan_control_commands |= IBMACPI_FAN_CMD_ENABLE;
+ fan_control_commands |= IBMACPI_FAN_CMD_LEVEL
+ | IBMACPI_FAN_CMD_ENABLE;
}
}
}
@@ -1838,9 +1842,20 @@ static int fan_read(char *p)
len += sprintf(p + len, "status:\t\tnot supported\n");
}
- if (fan_control_commands & IBMACPI_FAN_CMD_LEVEL)
- len += sprintf(p + len, "commands:\tlevel <level>"
- " (<level> is 0-7)\n");
+ if (fan_control_commands & IBMACPI_FAN_CMD_LEVEL) {
+ len += sprintf(p + len, "commands:\tlevel <level>");
+
+ switch (fan_control_access_mode) {
+ case IBMACPI_FAN_WR_ACPI_SFAN:
+ len += sprintf(p + len, " (<level> is 0-7)\n");
+ break;
+
+ default:
+ len += sprintf(p + len, " (<level> is 0-7, "
+ "auto, disengaged)\n");
+ break;
+ }
+ }
if (fan_control_commands & IBMACPI_FAN_CMD_ENABLE)
len += sprintf(p + len, "commands:\tenable, disable\n");
@@ -1863,6 +1878,17 @@ static int fan_write_level(int level)
return -EINVAL;
break;
+ case IBMACPI_FAN_WR_ACPI_FANS:
+ case IBMACPI_FAN_WR_TPEC:
+ if ((level != IBMACPI_FAN_EC_AUTO) &&
+ (level != IBMACPI_FAN_EC_DISENGAGED) &&
+ ((level < 0) || (level > 7)))
+ return -EINVAL;
+
+ if (!acpi_ec_write(fan_status_offset, level))
+ return -EIO;
+ break;
+
default:
printk(IBM_ERR "level command accepted for unsupported "
"access mode %d", fan_control_access_mode);
@@ -1876,7 +1902,13 @@ static int fan_write_enable( void )
switch (fan_control_access_mode) {
case IBMACPI_FAN_WR_ACPI_FANS:
case IBMACPI_FAN_WR_TPEC:
- if (!acpi_ec_write(fan_status_offset, 0x80))
+ if (!acpi_ec_write(fan_status_offset, IBMACPI_FAN_EC_AUTO))
+ return -EIO;
+ break;
+
+ case IBMACPI_FAN_WR_ACPI_SFAN:
+ /* For safety, handle enable as "level 7" */
+ if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", 7))
return -EIO;
break;
@@ -1897,6 +1929,11 @@ static int fan_write_disable( void )
return -EIO;
break;
+ case IBMACPI_FAN_WR_ACPI_SFAN:
+ if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", 0x00))
+ return -EIO;
+ break;
+
default:
printk(IBM_ERR "disable command accepted for unsupported "
"access mode %d", fan_control_access_mode);
@@ -1929,7 +1966,11 @@ static int fan_write_cmd_level(const cha
{
int level;
- if (sscanf(cmd, "level %d", &level) != 1)
+ if (strlencmp(cmd, "level auto") == 0)
+ level = IBMACPI_FAN_EC_AUTO;
+ else if (strlencmp(cmd, "level disengaged") == 0)
+ level = IBMACPI_FAN_EC_DISENGAGED;
+ else if (sscanf(cmd, "level %d", &level) != 1)
return 0;
*rc = fan_write_level(level);
Index: 2.6.18/Documentation/ibm-acpi.txt
===================================================================
--- 2.6.18.orig/Documentation/ibm-acpi.txt
+++ 2.6.18/Documentation/ibm-acpi.txt
@@ -602,27 +602,58 @@ directly accesses hardware registers and
WITH CAUTION! To use this feature, you need to supply the
experimental=1 parameter when loading the module.
-This feature attempts to show the current fan speed. The speed is read
-directly from the hardware registers of the embedded controller. This
-is known to work on later R, T and X series ThinkPads but may show a
-bogus value on other models.
+This feature attempts to show the current fan speed, control mode and
+other fan data that might be available. The speed is read directly
+from the hardware registers of the embedded controller. This is known
+to work on later R, T and X series ThinkPads but may show a bogus
+value on other models.
+
+Most ThinkPad fans work in "levels". Level 0 stops the fan. The
+higher the level, the higher the fan speed, although adjacent levels
+often map to the same fan speed. 7 is the highest level, where the
+fan reaches the maximum recommended speed. Level "auto" means the EC
+changes the fan level according to some internal algorithm, usually
+based on readings from the thermal sensors. Level "disengaged" means
+the EC disables the tachometer and drives the fan as fast as it can
+go, which might exceed hardware limits, so use this level with
+caution.
+
+The fan usually ramps up or down slowly from one speed to another,
+and it is normal for the EC to take several seconds to react to fan
+commands.
The fan may be enabled or disabled with the following commands:
echo enable >/proc/acpi/ibm/fan
echo disable >/proc/acpi/ibm/fan
+Placing a fan on level 0 is the same as disabling it. Enabling a fan
+places it either in level auto, or in level 7 depending on the ThinkPad
+model.
+
WARNING WARNING WARNING: do not leave the fan disabled unless you are
-monitoring the temperature sensor readings and you are ready to enable
-it if necessary to avoid overheating.
+monitoring all of the temperature sensor readings and you are ready to
+enable it if necessary to avoid overheating.
+
+An enabled fan in level "auto" may stop spinning if the EC decides the
+ThinkPad is cool enough and doesn't need the extra airflow. This is
+normal, and the EC will spin the fan up if the varios thermal readings
+rise too much.
+
+On the X40, this seems to depend on the CPU and HDD temperatures.
+Specifically, the fan is turned on when either the CPU temperature
+climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
+fan is turned off when the CPU temperature drops to 49 degrees and the
+HDD temperature drops to 41 degrees. These thresholds cannot
+currently be controlled.
-The fan only runs if it's enabled *and* the various temperature
-sensors which control it read high enough. On the X40, this seems to
-depend on the CPU and HDD temperatures. Specifically, the fan is
-turned on when either the CPU temperature climbs to 56 degrees or the
-HDD temperature climbs to 46 degrees. The fan is turned off when the
-CPU temperature drops to 49 degrees and the HDD temperature drops to
-41 degrees. These thresholds cannot currently be controlled.
+The fan level can be controlled with the command:
+
+ echo 'level <level>' > /proc/acpi/ibm/thermal
+
+Where <level> is an integer from 0 to 7, or one of the words "auto"
+or "disengaged" (without the quotes). Not all ThinkPads support the
+"auto" and "disengaged" levels.
On the X31 and X40 (and ONLY on those models), the fan speed can be
controlled to a certain degree. Once the fan is running, it can be
@@ -635,12 +666,9 @@ about 3700 to about 7350. Values outside
any effect or the fan speed eventually settles somewhere in that
range. The fan cannot be stopped or started with this command.
-On the 570, temperature readings are not available through this
-feature and the fan control works a little differently. The fan speed
-is reported in levels from 0 (off) to 7 (max) and can be controlled
-with the following command:
-
- echo 'level <level>' > /proc/acpi/ibm/thermal
+The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
+certain conditions are met. It will override any fan programming done
+through ibm-acpi.
Multiple Commands, Module Parameters
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh