Sent from Anson's iPhone
> 在 2013年12月23日，22:28，"Shawn Guo" <[email protected]> 写道： > >> On Mon, Dec 23, 2013 at 03:51:58PM -0500, Anson Huang wrote: >> Current imx thermal sensor's suspend function will return fail if >> thermal sensor is always enabled, but because alarm function is enabled, >> thermal sensor will be always enabled as well, hence break system's suspend, >> this patch will disable thermal sensor before suspend and re-enable it >> after resume, it fixes the failure of suspend/resume caused by thermal >> driver. > > We should probably make it clear in the commit log that it's a > regression caused by commit 37713a1 (thermal: imx: implement thermal > alarm interrupt handling). agreed, will improve the commit log in V2. > >> >> Signed-off-by: Anson Huang <[email protected]> >> --- >> drivers/thermal/imx_thermal.c | 31 +++++++++++++++++-------------- >> 1 file changed, 17 insertions(+), 14 deletions(-) >> >> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c >> index cbb16f3..9a9a6c2 100644 >> --- a/drivers/thermal/imx_thermal.c >> +++ b/drivers/thermal/imx_thermal.c >> @@ -510,27 +510,30 @@ static int imx_thermal_suspend(struct device *dev) >> { >> struct imx_thermal_data *data = dev_get_drvdata(dev); >> struct regmap *map = data->tempmon; >> - u32 val; >> >> - regmap_read(map, TEMPSENSE0, &val); >> - if ((val & TEMPSENSE0_POWER_DOWN) == 0) { >> - /* >> - * If a measurement is taking place, wait for a long enough >> - * time for it to finish, and then check again. If it still >> - * does not finish, something must go wrong. >> - */ >> - udelay(50); >> - regmap_read(map, TEMPSENSE0, &val); >> - if ((val & TEMPSENSE0_POWER_DOWN) == 0) >> - return -ETIMEDOUT; >> - } >> + /* >> + * Need to disable thermal sensor, otherwise, when thermal core >> + * try to get temperature before thermal sensor resume, a wrong >> + * temperature will be read as the thermal sensor is powered >> + * down. >> + */ >> + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP); >> + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); >> + data->mode = THERMAL_DEVICE_DISABLED; > > Is it really necessary to update data->mode through suspend/resume > cycle? Yes, as the thermal core may try to get temperature before imx thermal sensor resume, if not setting its mode to disabled, thermal core will get a wrong temp and caused system power off by mistake, as the get_temp function will decide whether to power up thermal core according to its mode. > > Shawn > >> >> return 0; >> } >> >> static int imx_thermal_resume(struct device *dev) >> { >> - /* Nothing to do for now */ >> + struct imx_thermal_data *data = dev_get_drvdata(dev); >> + struct regmap *map = data->tempmon; >> + >> + /* Enabled thermal sensor after resume */ >> + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); >> + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); >> + data->mode = THERMAL_DEVICE_ENABLED; >> + >> return 0; >> } >> #endif >> -- >> 1.7.9.5 >
