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| author | Amit Kucheria <amit.kucheria@linaro.org> | 2018-07-26 16:03:10 +0530 |
|---|---|---|
| committer | Eduardo Valentin <edubezval@gmail.com> | 2018-07-27 15:16:55 -0700 |
| commit | 432121adf5e880240237bd9b15ec0ab995d7ea1f (patch) | |
| tree | 2a4115a3bd6ad2ffc9f810b88d09c3252ef323bd /drivers/thermal | |
| parent | faa590baf8dfe5ad877e062f18de4419e4d174f7 (diff) | |
| download | lwn-432121adf5e880240237bd9b15ec0ab995d7ea1f.tar.gz lwn-432121adf5e880240237bd9b15ec0ab995d7ea1f.zip | |
thermal: tsens: Fix negative temperature reporting
The current code will always return 0xffffffff in case of negative
temperatures due to a bug in how the binary sign extension is being done.
Use sign_extend32() instead.
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Diffstat (limited to 'drivers/thermal')
| -rw-r--r-- | drivers/thermal/qcom/tsens-v2.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/drivers/thermal/qcom/tsens-v2.c b/drivers/thermal/qcom/tsens-v2.c index 908e3dcb2d5c..44da02f594ac 100644 --- a/drivers/thermal/qcom/tsens-v2.c +++ b/drivers/thermal/qcom/tsens-v2.c @@ -5,19 +5,20 @@ */ #include <linux/regmap.h> +#include <linux/bitops.h> #include "tsens.h" #define STATUS_OFFSET 0xa0 #define LAST_TEMP_MASK 0xfff #define STATUS_VALID_BIT BIT(21) -#define CODE_SIGN_BIT BIT(11) static int get_temp_tsens_v2(struct tsens_device *tmdev, int id, int *temp) { struct tsens_sensor *s = &tmdev->sensor[id]; u32 code; unsigned int status_reg; - int last_temp = 0, last_temp2 = 0, last_temp3 = 0, ret; + u32 last_temp = 0, last_temp2 = 0, last_temp3 = 0; + int ret; status_reg = tmdev->tm_offset + STATUS_OFFSET + s->hw_id * 4; ret = regmap_read(tmdev->map, status_reg, &code); @@ -54,12 +55,8 @@ static int get_temp_tsens_v2(struct tsens_device *tmdev, int id, int *temp) else if (last_temp2 == last_temp3) last_temp = last_temp3; done: - /* Code sign bit is the sign extension for a negative value */ - if (last_temp & CODE_SIGN_BIT) - last_temp |= ~CODE_SIGN_BIT; - - /* Temperatures are in deciCelicius */ - *temp = last_temp * 100; + /* Convert temperature from deciCelsius to milliCelsius */ + *temp = sign_extend32(last_temp, fls(LAST_TEMP_MASK) - 1) * 100; return 0; } |