acerhdf: Use bang-bang thermal governor

acerhdf has been doing an on-off fan control using hysteresis by
post-manipulating the outcome of thermal subsystem trip point handling.
This patch enables acerhdf to use the bang-bang governor, which is
intended for on-off controlled fans.

Cc: platform-driver-x86@vger.kernel.org
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
CC: Zhang Rui <rui.zhang@intel.com>
Cc: Andreas Mohr <andi@lisas.de>
Cc: Javi Merino <javi.merino@arm.com>
Acked-and-tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Feuerer <peter@piie.net>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 854cc5049b6986d843838c9276f7f7a2e8bf1263..ba7761107d8360a508a22d65a0c561e9a66f3309 100644 (file)
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -38,7 +38,8 @@ config ACER_WMI
 
 config ACERHDF
        tristate "Acer Aspire One temperature and fan driver"
-       depends on THERMAL && ACPI
+       select THERMAL_GOV_BANG_BANG
+       depends on ACPI
        ---help---
          This is a driver for Acer Aspire One netbooks. It allows to access
          the temperature sensor and to control the fan.

diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
index f30767fb4521709a8bcc5fa89064b99f1b082ab6..7fe7dbf2f4ef2644c352f1bd1d279074df97da8a 100644 (file)
--- a/drivers/platform/x86/acerhdf.c
+++ b/drivers/platform/x86/acerhdf.c
@@ -50,7 +50,7 @@
  */
 #undef START_IN_KERNEL_MODE
 
-#define DRV_VER "0.5.30"
+#define DRV_VER "0.7.0"
 
 /*
  * According to the Atom N270 datasheet,
@@ -258,6 +258,14 @@ static const struct bios_settings_t bios_tbl[] = {
 
 static const struct bios_settings_t *bios_cfg __read_mostly;
 
+/*
+ * this struct is used to instruct thermal layer to use bang_bang instead of
+ * default governor for acerhdf
+ */
+static struct thermal_zone_params acerhdf_zone_params = {
+       .governor_name = "bang_bang",
+};
+
 static int acerhdf_get_temp(int *temp)
 {
        u8 read_temp;
@@ -439,6 +447,17 @@ static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
        return 0;
 }
 
+static int acerhdf_get_trip_hyst(struct thermal_zone_device *thermal, int trip,
+                                unsigned long *temp)
+{
+       if (trip != 0)
+               return -EINVAL;
+
+       *temp = fanon - fanoff;
+
+       return 0;
+}
+
 static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
                                 unsigned long *temp)
 {
@@ -463,6 +482,7 @@ static struct thermal_zone_device_ops acerhdf_dev_ops = {
        .get_mode = acerhdf_get_mode,
        .set_mode = acerhdf_set_mode,
        .get_trip_type = acerhdf_get_trip_type,
+       .get_trip_hyst = acerhdf_get_trip_hyst,
        .get_trip_temp = acerhdf_get_trip_temp,
        .get_crit_temp = acerhdf_get_crit_temp,
 };
@@ -515,9 +535,7 @@ static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
        }
 
        if (state == 0) {
-               /* turn fan off only if below fanoff temperature */
-               if ((cur_state == ACERHDF_FAN_AUTO) &&
-                   (cur_temp < fanoff))
+               if (cur_state == ACERHDF_FAN_AUTO)
                        acerhdf_change_fanstate(ACERHDF_FAN_OFF);
        } else {
                if (cur_state == ACERHDF_FAN_OFF)
@@ -696,11 +714,19 @@ static int acerhdf_register_thermal(void)
                return -EINVAL;
 
        thz_dev = thermal_zone_device_register("acerhdf", 1, 0, NULL,
-                                             &acerhdf_dev_ops, NULL, 0,
+                                             &acerhdf_dev_ops,
+                                             &acerhdf_zone_params, 0,
                                              (kernelmode) ? interval*1000 : 0);
        if (IS_ERR(thz_dev))
                return -EINVAL;
 
+       if (strcmp(thz_dev->governor->name,
+                               acerhdf_zone_params.governor_name)) {
+               pr_err("Didn't get thermal governor %s, perhaps not compiled into thermal subsystem.\n",
+                               acerhdf_zone_params.governor_name);
+               return -EINVAL;
+       }
+
        return 0;
 }