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

Ivan T. Ivanov
2014-09-29T13:54:25Z

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 ‘qpnp_tm_update_temp_no_adc’:
> drivers/thermal/qpnp-temp-alarm.c:135:8: warning: ‘reg’ 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.

>
> > +
> > + if (stage > chip->stage) {
> > + /* increasing stage, use lower bound */
> > + chip->temp = (stage - 1) * TEMP_STAGE_STEP +
> > + chip->thresh * TEMP_THRESH_STEP +
> > + TEMP_STAGE_HYSTERESIS + TEMP_THRESH_MIN;
> > + } else if (stage < chip->stage) {
> > + /* decreasing stage, use upper bound */
> > + chip->temp = stage * TEMP_STAGE_STEP +
> > + chip->thresh * TEMP_THRESH_STEP -
> > + TEMP_STAGE_HYSTERESIS + TEMP_THRESH_MIN;
> > + }
> > +
> > + chip->stage = stage;
> > +
> > + return 0;
> > +}
> > +
>
> <snip>
>
> > +
> > +#define QPNP_TM_PM_OPS (&qpnp_tm_pm_ops)
> > +#else
> > +#define QPNP_TM_PM_OPS NULL
> > +#endif
> > +
> > +static struct of_device_id qpnp_tm_match_table[] = {
>
> It must be static const struct of_device_id, because all OF functions handle it as const.

Sure, will fix it.

Thank you,
Ivan