Re: [PATCH v3 net-next 06/15] ptp: netc: add periodic pulse output support

[kernel test robot <lkp@intel.com>]

Hi Wei,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Wei-Fang/dt-bindings-ptp-add-NETC-Timer-PTP-clock/20250812-181510
base:   net-next/main
patch link:    https://lore.kernel.org/r/20250812094634.489901-7-wei.fang%40nxp.com
patch subject: [PATCH v3 net-next 06/15] ptp: netc: add periodic pulse output support
config: loongarch-allyesconfig (https://download.01.org/0day-ci/archive/20250813/202508131027.y3pyBEJQ-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 3769ce013be2879bf0b329c14a16f5cb766f26ce)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250813/202508131027.y3pyBEJQ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508131027.y3pyBEJQ-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/ptp/ptp_netc.c:394:33: warning: variable 'pp' is uninitialized when used here [-Wuninitialized]
     394 |                 priv->fs_alarm_bitmap &= ~BIT(pp->alarm_id);
         |                                               ^~
   drivers/ptp/ptp_netc.c:348:20: note: initialize the variable 'pp' to silence this warning
     348 |         struct netc_pp *pp;
         |                           ^
         |                            = NULL
   1 warning generated.


vim +/pp +394 drivers/ptp/ptp_netc.c

   337	
   338	/* Note that users should not use this API to output PPS signal on
   339	 * external pins, because PTP_CLK_REQ_PPS trigger internal PPS event
   340	 * for input into kernel PPS subsystem. See:
   341	 * https://lore.kernel.org/r/20201117213826.18235-1-a.fatoum@pengutronix.de
   342	 */
   343	static int netc_timer_enable_pps(struct netc_timer *priv,
   344					 struct ptp_clock_request *rq, int on)
   345	{
   346		struct device *dev = &priv->pdev->dev;
   347		unsigned long flags;
   348		struct netc_pp *pp;
   349		int err = 0;
   350	
   351		spin_lock_irqsave(&priv->lock, flags);
   352	
   353		if (on) {
   354			int alarm_id;
   355			u8 channel;
   356	
   357			if (priv->pps_channel < NETC_TMR_FIPER_NUM) {
   358				channel = priv->pps_channel;
   359			} else {
   360				channel = netc_timer_select_pps_channel(priv);
   361				if (channel == NETC_TMR_INVALID_CHANNEL) {
   362					dev_err(dev, "No available FIPERs\n");
   363					err = -EBUSY;
   364					goto unlock_spinlock;
   365				}
   366			}
   367	
   368			pp = &priv->pp[channel];
   369			if (pp->enabled)
   370				goto unlock_spinlock;
   371	
   372			alarm_id = netc_timer_get_alarm_id(priv);
   373			if (alarm_id == priv->fs_alarm_num) {
   374				dev_err(dev, "No available ALARMs\n");
   375				err = -EBUSY;
   376				goto unlock_spinlock;
   377			}
   378	
   379			pp->enabled = true;
   380			pp->type = NETC_PP_PPS;
   381			pp->alarm_id = alarm_id;
   382			pp->period = NSEC_PER_SEC;
   383			priv->pps_channel = channel;
   384	
   385			netc_timer_enable_periodic_pulse(priv, channel);
   386		} else {
   387			/* pps_channel is invalid if PPS is not enabled, so no
   388			 * processing is needed.
   389			 */
   390			if (priv->pps_channel >= NETC_TMR_FIPER_NUM)
   391				goto unlock_spinlock;
   392	
   393			netc_timer_disable_periodic_pulse(priv, priv->pps_channel);
 > 394			priv->fs_alarm_bitmap &= ~BIT(pp->alarm_id);
   395			pp = &priv->pp[priv->pps_channel];
   396			memset(pp, 0, sizeof(*pp));
   397			priv->pps_channel = NETC_TMR_INVALID_CHANNEL;
   398		}
   399	
   400	unlock_spinlock:
   401		spin_unlock_irqrestore(&priv->lock, flags);
   402	
   403		return err;
   404	}
   405	

-- 
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