From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amit Kucheria Subject: [PATCH v2 3/3] thermal: tsens: Fix negative temperature reporting Date: Thu, 26 Jul 2018 16:03:10 +0530 Message-ID: <52516c287c9455676e7cbde4a4fa94282d73367f.1532600791.git.amit.kucheria@linaro.org> References: Return-path: In-Reply-To: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: rnayak@codeaurora.org, linux-arm-msm@vger.kernel.org, bjorn.andersson@linaro.org, edubezval@gmail.com, smohanad@codeaurora.org, andy.gross@linaro.org, dianders@chromium.org, mka@chromium.org, Zhang Rui , linux-pm@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org 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 Reviewed-by: Matthias Kaehlcke --- drivers/thermal/qcom/tsens-v2.c | 13 +++++-------- 1 file 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 +#include #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; } -- 2.17.GIT