From 185673ca71d3f7e9c7d62ee5084348e084352e56 Mon Sep 17 00:00:00 2001 From: "Nícolas F. R. A. Prado" Date: Thu, 13 Jul 2023 11:42:37 -0400 Subject: thermal/drivers/mediatek/lvts_thermal: Make readings valid in filtered mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Reviewed-by: Chen-Yu Tsai Tested-by: Chen-Yu Tsai Signed-off-by: Nícolas F. R. A. Prado Reviewed-by: Alexandre Mergnat Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20230713154743.611870-1-nfraprado@collabora.com --- drivers/thermal/mediatek/lvts_thermal.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'drivers/thermal') diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c index f4709ae842a2..effd9b00a424 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 0x8300318C @@ -86,6 +86,9 @@ #define LVTS_MSR_IMMEDIATE_MODE 0 #define LVTS_MSR_FILTERED_MODE 1 +#define LVTS_MSR_READ_TIMEOUT_US 400 +#define LVTS_MSR_READ_WAIT_US (LVTS_MSR_READ_TIMEOUT_US / 2) + #define LVTS_HW_SHUTDOWN_MT8195 105000 #define LVTS_MINIMUM_THRESHOLD 20000 @@ -268,6 +271,7 @@ 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: @@ -280,7 +284,8 @@ 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), + LVTS_MSR_READ_WAIT_US, LVTS_MSR_READ_TIMEOUT_US); /* * As the thermal zone temperature will read before the @@ -293,7 +298,7 @@ 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); -- cgit v1.2.3