| Message ID | 20230706161509.204546-1-nfraprado@collabora.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | thermal/drivers/mediatek/lvts_thermal: Make readings valid in filtered mode | expand |
Il 06/07/23 18:14, Nícolas F. R. A. Prado ha scritto: > Currently, when a controller is configured to use filtered mode, thermal > readings are valid only about 30% of the time. > > Upon testing, it was noticed that lowering any of the interval settings > resulted in an improved rate of valid data. The same was observed when > decreasing the number of samples for each sensor (which also results in > quicker measurements). > > Retrying the read with a timeout longer than the time it takes to > resample (about 344us with these settings and 4 sensors) also improves > the rate. > > Lower all timing settings to the minimum, configure the filtering to > single sample, and poll the measurement register for at least one period > to improve the data validity on filtered mode. With these changes in > place, out of 100000 reads, a single one failed, ie 99.999% of the data > was valid. > > Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> > > --- > > drivers/thermal/mediatek/lvts_thermal.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c > index 1e11defe4f35..b5fb1d8bc3d8 100644 > --- a/drivers/thermal/mediatek/lvts_thermal.c > +++ b/drivers/thermal/mediatek/lvts_thermal.c > @@ -58,11 +58,11 @@ > #define LVTS_PROTTC(__base) (__base + 0x00CC) > #define LVTS_CLKEN(__base) (__base + 0x00E4) > > -#define LVTS_PERIOD_UNIT ((118 * 1000) / (256 * 38)) > -#define LVTS_GROUP_INTERVAL 1 > -#define LVTS_FILTER_INTERVAL 1 > -#define LVTS_SENSOR_INTERVAL 1 > -#define LVTS_HW_FILTER 0x2 > +#define LVTS_PERIOD_UNIT 0 > +#define LVTS_GROUP_INTERVAL 0 > +#define LVTS_FILTER_INTERVAL 0 > +#define LVTS_SENSOR_INTERVAL 0 > +#define LVTS_HW_FILTER 0x0 > #define LVTS_TSSEL_CONF 0x13121110 > #define LVTS_CALSCALE_CONF 0x300 > #define LVTS_MONINT_CONF 0x9FBF7BDE > @@ -257,6 +257,7 @@ static int lvts_get_temp(struct thermal_zone_device *tz, int *temp) > struct lvts_sensor *lvts_sensor = thermal_zone_device_priv(tz); > void __iomem *msr = lvts_sensor->msr; > u32 value; > + int rc; > > /* > * Measurement registers: > @@ -269,7 +270,7 @@ static int lvts_get_temp(struct thermal_zone_device *tz, int *temp) > * 16 : Valid temperature > * 15-0 : Raw temperature > */ > - value = readl(msr); #define LVTS_MSR_READ_TIMEOUT_US 400 then, either 240 like this... #define LVTS_MSR_READ_WAIT_US ((LVTS_MSR_READ_TIMEOUT_US / 2) - 10) ..or 220 (if valid) like this.. #define LVTS_MSR_READ_WAIT_US ((LVTS_MSR_READ_TIMEOUT_US / 20) + \ (LVTS_MSR_READ_TIMEOUT_US / 2)) ..or just "240-and-that's-it" #define LVTS_MSR_READ_WAIT_US 240 rc = readl_poll_timeout(msr, value, value & BIT(16), LVTS_MSR_READ_WAIT_US, LVTS_MSR_READ_TIMEOUT_US); Cheers, Angelo
diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c index 1e11defe4f35..b5fb1d8bc3d8 100644 --- a/drivers/thermal/mediatek/lvts_thermal.c +++ b/drivers/thermal/mediatek/lvts_thermal.c @@ -58,11 +58,11 @@ #define LVTS_PROTTC(__base) (__base + 0x00CC) #define LVTS_CLKEN(__base) (__base + 0x00E4) -#define LVTS_PERIOD_UNIT ((118 * 1000) / (256 * 38)) -#define LVTS_GROUP_INTERVAL 1 -#define LVTS_FILTER_INTERVAL 1 -#define LVTS_SENSOR_INTERVAL 1 -#define LVTS_HW_FILTER 0x2 +#define LVTS_PERIOD_UNIT 0 +#define LVTS_GROUP_INTERVAL 0 +#define LVTS_FILTER_INTERVAL 0 +#define LVTS_SENSOR_INTERVAL 0 +#define LVTS_HW_FILTER 0x0 #define LVTS_TSSEL_CONF 0x13121110 #define LVTS_CALSCALE_CONF 0x300 #define LVTS_MONINT_CONF 0x9FBF7BDE @@ -257,6 +257,7 @@ static int lvts_get_temp(struct thermal_zone_device *tz, int *temp) struct lvts_sensor *lvts_sensor = thermal_zone_device_priv(tz); void __iomem *msr = lvts_sensor->msr; u32 value; + int rc; /* * Measurement registers: @@ -269,7 +270,7 @@ static int lvts_get_temp(struct thermal_zone_device *tz, int *temp) * 16 : Valid temperature * 15-0 : Raw temperature */ - value = readl(msr); + rc = readl_poll_timeout(msr, value, value & BIT(16), 240, 400); /* * As the thermal zone temperature will read before the @@ -282,7 +283,7 @@ static int lvts_get_temp(struct thermal_zone_device *tz, int *temp) * functionning temperature and directly jump to a system * shutdown. */ - if (!(value & BIT(16))) + if (rc) return -EAGAIN; *temp = lvts_raw_to_temp(value & 0xFFFF);
Currently, when a controller is configured to use filtered mode, thermal readings are valid only about 30% of the time. Upon testing, it was noticed that lowering any of the interval settings resulted in an improved rate of valid data. The same was observed when decreasing the number of samples for each sensor (which also results in quicker measurements). Retrying the read with a timeout longer than the time it takes to resample (about 344us with these settings and 4 sensors) also improves the rate. Lower all timing settings to the minimum, configure the filtering to single sample, and poll the measurement register for at least one period to improve the data validity on filtered mode. With these changes in place, out of 100000 reads, a single one failed, ie 99.999% of the data was valid. Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> --- drivers/thermal/mediatek/lvts_thermal.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)