diff options
| author | Martin Blumenstingl <martin.blumenstingl@googlemail.com> | 2022-10-24 00:31:57 +0300 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2022-12-05 03:45:02 +0300 |
| commit | 084ed144c448fd5bc8ed5a58247153fbbfd115c3 (patch) | |
| tree | 993820792b3311d724f18c335a78678929e259a4 /drivers/hwmon | |
| parent | 8f2fa4726faf01094d7a5be7bd0c120c565f54d9 (diff) | |
| download | linux-084ed144c448fd5bc8ed5a58247153fbbfd115c3.tar.xz | |
hwmon: (jc42) Restore the min/max/critical temperatures on resume
The JC42 compatible thermal sensor on Kingston KSM32ES8/16ME DIMMs
(using Micron E-Die) is an ST Microelectronics STTS2004 (manufacturer
0x104a, device 0x2201). It does not keep the previously programmed
minimum, maximum and critical temperatures after system suspend and
resume (which is a shutdown / startup cycle for the JC42 temperature
sensor). This results in an alarm on system resume because the hardware
default for these values is 0°C (so any environment temperature greater
than 0°C will trigger the alarm).
Example before system suspend:
jc42-i2c-0-1a
Adapter: SMBus PIIX4 adapter port 0 at 0b00
temp1: +34.8°C (low = +0.0°C)
(high = +85.0°C, hyst = +85.0°C)
(crit = +95.0°C, hyst = +95.0°C)
Example after system resume (without this change):
jc42-i2c-0-1a
Adapter: SMBus PIIX4 adapter port 0 at 0b00
temp1: +34.8°C (low = +0.0°C) ALARM (HIGH, CRIT)
(high = +0.0°C, hyst = +0.0°C)
(crit = +0.0°C, hyst = +0.0°C)
Apply the cached values from the JC42_REG_TEMP_UPPER,
JC42_REG_TEMP_LOWER, JC42_REG_TEMP_CRITICAL and JC42_REG_SMBUS (where
the SMBUS register is not related to this issue but a side-effect of
using regcache_sync() during system resume with the previously
cached/programmed values. This fixes the alarm due to the hardware
defaults of 0°C because the previously applied limits (set by userspace)
are re-applied on system resume.
Fixes: 175c490c9e7f ("hwmon: (jc42) Add support for STTS2004 and AT30TSE004")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20221023213157.11078-3-martin.blumenstingl@googlemail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/jc42.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c index 355639d208d0..0554b41c32bc 100644 --- a/drivers/hwmon/jc42.c +++ b/drivers/hwmon/jc42.c @@ -578,6 +578,10 @@ static int jc42_suspend(struct device *dev) data->config |= JC42_CFG_SHUTDOWN; regmap_write(data->regmap, JC42_REG_CONFIG, data->config); + + regcache_cache_only(data->regmap, true); + regcache_mark_dirty(data->regmap); + return 0; } @@ -585,9 +589,13 @@ static int jc42_resume(struct device *dev) { struct jc42_data *data = dev_get_drvdata(dev); + regcache_cache_only(data->regmap, false); + data->config &= ~JC42_CFG_SHUTDOWN; regmap_write(data->regmap, JC42_REG_CONFIG, data->config); - return 0; + + /* Restore cached register values to hardware */ + return regcache_sync(data->regmap); } static const struct dev_pm_ops jc42_dev_pm_ops = { |