Re: [PATCH v2] thermal: Add QPNP PMIC temperature alarm driver

[Ivan T. Ivanov]

On Tue, 2014-09-30 at 10:00 +0530, Kiran Padwal wrote:
> On Monday 29 September 2014 07:24 PM, Ivan T. Ivanov wrote:
> > On Fri, 2014-09-26 at 16:51 +0530, Kiran Padwal wrote:
> >> On Thursday 25 September 2014 07:00 PM, Ivan T. Ivanov wrote:
> >>> Add support for the temperature alarm peripheral found inside
> >>> Qualcomm plug-and-play (QPNP) PMIC chips.  The temperature alarm
> >>> peripheral outputs a pulse on an interrupt line whenever the
> >>> thermal over temperature stage value changes.  Implement an ISR
> >>> to manage this interrupt.
> >>>
> >>
> >> <snip>
> >>
> >>> + * This function updates the internal temp value based on the
> >>> + * current thermal stage and threshold as well as the previous stage
> >>> + */
> >>> +static int qpnp_tm_update_temp_no_adc(struct qpnp_tm_chip *chip)
> >>> +{
> >>> +	unsigned int stage;
> >>> +	int rc;
> >>> +	u8 reg;
> >>> +
> >>> +	rc = qpnp_tm_read(chip, QPNP_TM_REG_STATUS, &reg);
> >>> +	if (rc < 0)
> >>> +		return rc;
> >>> +
> >>> +	stage = reg & STATUS_STAGE_MASK;
> >>
> >> During compilation, getting a waring as below,
> >>
> >> drivers/thermal/qpnp-temp-alarm.c: In function âqpnp_tm_update_temp_no_adcâ:
> >> drivers/thermal/qpnp-temp-alarm.c:135:8: warning: âregâ may be used uninitialized in this function [-Wmaybe-uninitialized]
> >>   stage = reg & STATUS_STAGE_MASK;
> > 
> > Could you share compiler version and options which you are using.
> > I am unable to trigger this warning. Looking code I can not 
> > see how this could happen.
> 
> I have Linaro cross tool chain with version-4.8.3 and I am simply doing "make zImage" without any option.

Hm, no warnings with arm-unknown-linux-gnueabi-gcc (GCC) 4.6.3 and
arm-linux-gnueabihf-gcc (crosstool-NG linaro-1.13.1-4.9-2014.09, but
indeed arm-linux-gnueabihf-gcc (crosstool-NG linaro-1.13.1-4.8-2014.03.

I will say that this is false positive :-). Please update your tool-chain.

Regards,
Ivan


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