Re: [PATCH 02/15] gpio: adnp: use lock guards for the I2C lock

[kernel test robot <lkp@xxxxxxxxx>]

Hi Bartosz,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 9778568dede2166c7bd124d473f9ec365f782935]

url:    https://github.com/intel-lab-lkp/linux/commits/Bartosz-Golaszewski/gpio-74x164-use-new-line-value-setter-callbacks/20250303-212738
base:   9778568dede2166c7bd124d473f9ec365f782935
patch link:    https://lore.kernel.org/r/20250303-gpiochip-set-conversion-v1-2-1d5cceeebf8b%40linaro.org
patch subject: [PATCH 02/15] gpio: adnp: use lock guards for the I2C lock
config: x86_64-buildonly-randconfig-001-20250304 (https://download.01.org/0day-ci/archive/20250304/202503041612.G8O0Bdrg-lkp@xxxxxxxxx/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250304/202503041612.G8O0Bdrg-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503041612.G8O0Bdrg-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

>> drivers/gpio/gpio-adnp.c:241:8: warning: variable 'isr' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
     241 |                         if (err < 0)
         |                             ^~~~~~~
   drivers/gpio/gpio-adnp.c:265:14: note: uninitialized use occurs here
     265 |                 pending &= isr & ier;
         |                            ^~~
   drivers/gpio/gpio-adnp.c:241:4: note: remove the 'if' if its condition is always false
     241 |                         if (err < 0)
         |                         ^~~~~~~~~~~~
     242 |                                 continue;
         |                                 ~~~~~~~~
   drivers/gpio/gpio-adnp.c:235:25: note: initialize the variable 'isr' to silence this warning
     235 |                 u8 changed, level, isr, ier;
         |                                       ^
         |                                        = '\0'
>> drivers/gpio/gpio-adnp.c:245:8: warning: variable 'ier' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
     245 |                         if (err < 0)
         |                             ^~~~~~~
   drivers/gpio/gpio-adnp.c:265:20: note: uninitialized use occurs here
     265 |                 pending &= isr & ier;
         |                                  ^~~
   drivers/gpio/gpio-adnp.c:245:4: note: remove the 'if' if its condition is always false
     245 |                         if (err < 0)
         |                         ^~~~~~~~~~~~
     246 |                                 continue;
         |                                 ~~~~~~~~
   drivers/gpio/gpio-adnp.c:241:8: warning: variable 'ier' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
     241 |                         if (err < 0)
         |                             ^~~~~~~
   drivers/gpio/gpio-adnp.c:265:20: note: uninitialized use occurs here
     265 |                 pending &= isr & ier;
         |                                  ^~~
   drivers/gpio/gpio-adnp.c:241:4: note: remove the 'if' if its condition is always false
     241 |                         if (err < 0)
         |                         ^~~~~~~~~~~~
     242 |                                 continue;
         |                                 ~~~~~~~~
   drivers/gpio/gpio-adnp.c:235:30: note: initialize the variable 'ier' to silence this warning
     235 |                 u8 changed, level, isr, ier;
         |                                            ^
         |                                             = '\0'
   3 warnings generated.


vim +241 drivers/gpio/gpio-adnp.c

   225	
   226	static irqreturn_t adnp_irq(int irq, void *data)
   227	{
   228		struct adnp *adnp = data;
   229		unsigned int num_regs, i;
   230	
   231		num_regs = 1 << adnp->reg_shift;
   232	
   233		for (i = 0; i < num_regs; i++) {
   234			unsigned int base = i << adnp->reg_shift, bit;
   235			u8 changed, level, isr, ier;
   236			unsigned long pending;
   237			int err;
   238	
   239			scoped_guard(mutex, &adnp->i2c_lock) {
   240				err = adnp_read(adnp, GPIO_PLR(adnp) + i, &level);
 > 241				if (err < 0)
   242					continue;
   243	
   244				err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr);
 > 245				if (err < 0)
   246					continue;
   247	
   248				err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier);
   249				if (err < 0)
   250					continue;
   251			}
   252	
   253			/* determine pins that changed levels */
   254			changed = level ^ adnp->irq_level[i];
   255	
   256			/* compute edge-triggered interrupts */
   257			pending = changed & ((adnp->irq_fall[i] & ~level) |
   258					     (adnp->irq_rise[i] & level));
   259	
   260			/* add in level-triggered interrupts */
   261			pending |= (adnp->irq_high[i] & level) |
   262				   (adnp->irq_low[i] & ~level);
   263	
   264			/* mask out non-pending and disabled interrupts */
   265			pending &= isr & ier;
   266	
   267			for_each_set_bit(bit, &pending, 8) {
   268				unsigned int child_irq;
   269				child_irq = irq_find_mapping(adnp->gpio.irq.domain,
   270							     base + bit);
   271				handle_nested_irq(child_irq);
   272			}
   273		}
   274	
   275		return IRQ_HANDLED;
   276	}
   277	

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