drivers/gpu/drm/i915/i915_hwmon.c:69 hwm_in_read() error: uninitialized symbol 'reg_value'.

[Dan Carpenter]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   033c40a89f55525139fd5b6342281b09b97d05bf
commit: f8572bb675250ee527d9ba35fa1ce17480407399 drm/i915/hwmon: Add HWMON current voltage support
config: x86_64-randconfig-m001-20230213 (https://download.01.org/0day-ci/archive/20230216/202302161256.eeoRFhSo-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>
| Link: https://lore.kernel.org/r/202302161256.eeoRFhSo-lkp@xxxxxxxxx/

smatch warnings:
drivers/gpu/drm/i915/i915_hwmon.c:69 hwm_in_read() error: uninitialized symbol 'reg_value'.

vim +/reg_value +69 drivers/gpu/drm/i915/i915_hwmon.c

f8572bb675250e Riana Tauro 2022-10-13  57  static int
f8572bb675250e Riana Tauro 2022-10-13  58  hwm_in_read(struct hwm_drvdata *ddat, u32 attr, long *val)
f8572bb675250e Riana Tauro 2022-10-13  59  {
f8572bb675250e Riana Tauro 2022-10-13  60  	struct i915_hwmon *hwmon = ddat->hwmon;
f8572bb675250e Riana Tauro 2022-10-13  61  	intel_wakeref_t wakeref;
f8572bb675250e Riana Tauro 2022-10-13  62  	u32 reg_value;
f8572bb675250e Riana Tauro 2022-10-13  63  
f8572bb675250e Riana Tauro 2022-10-13  64  	switch (attr) {
f8572bb675250e Riana Tauro 2022-10-13  65  	case hwmon_in_input:
f8572bb675250e Riana Tauro 2022-10-13  66  		with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
f8572bb675250e Riana Tauro 2022-10-13  67  			reg_value = intel_uncore_read(ddat->uncore, hwmon->rg.gt_perf_status);

The with_intel_runtime_pm() macro is a complicated if statement, but
written as a for loop so it can do a get() and a put()?  reg_value is
not initialized in the without pm case.

f8572bb675250e Riana Tauro 2022-10-13  68  		/* HW register value in units of 2.5 millivolt */
f8572bb675250e Riana Tauro 2022-10-13 @69  		*val = DIV_ROUND_CLOSEST(REG_FIELD_GET(GEN12_VOLTAGE_MASK, reg_value) * 25, 10);
f8572bb675250e Riana Tauro 2022-10-13  70  		return 0;
f8572bb675250e Riana Tauro 2022-10-13  71  	default:
f8572bb675250e Riana Tauro 2022-10-13  72  		return -EOPNOTSUPP;
f8572bb675250e Riana Tauro 2022-10-13  73  	}
f8572bb675250e Riana Tauro 2022-10-13  74  }

-- 
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https://github.com/intel/lkp-tests