| Message ID | 20221021165000.1865615-3-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | hwmon: (jc42) regmap conversion and resume fix | expand |
On Fri, Oct 21, 2022 at 06:50:00PM +0200, Martin Blumenstingl wrote: > 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") > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Nice use of regmap. For my reference: Reviewed-by: Guenter Roeck <linux@roeck-us.net> Thanks, Guenter > --- > drivers/hwmon/jc42.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c > index 8d70960d5444..52a60eb0791b 100644 > --- a/drivers/hwmon/jc42.c > +++ b/drivers/hwmon/jc42.c > @@ -565,6 +565,10 @@ 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; > } > > @@ -572,9 +576,13 @@ 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 = { > -- > 2.38.1 >
diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c index 8d70960d5444..52a60eb0791b 100644 --- a/drivers/hwmon/jc42.c +++ b/drivers/hwmon/jc42.c @@ -565,6 +565,10 @@ 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; } @@ -572,9 +576,13 @@ 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 = {
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") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> --- drivers/hwmon/jc42.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)