[Intel-gfx] [PATCH] drm/i915/hwmon: Silence UBSAN uninitialized bool variable warning

[Ashutosh Dixit]

Loading i915 on UBSAN enabled kernels (CONFIG_UBSAN/CONFIG_UBSAN_BOOL)
causes the following warning:

  UBSAN: invalid-load in drivers/gpu/drm/i915/gt/uc/intel_uc.c:558:2
  load of value 255 is not a valid value for type '_Bool'
  Call Trace:
   dump_stack_lvl+0x57/0x7d
   ubsan_epilogue+0x5/0x40
   __ubsan_handle_load_invalid_value.cold+0x43/0x48
   __uc_init_hw+0x76a/0x903 [i915]
   ...
   i915_driver_probe+0xfb1/0x1eb0 [i915]
   i915_pci_probe+0xbe/0x2d0 [i915]

The warning happens because during probe i915_hwmon is still not available
which results in the output boolean variable *old remaining
uninitialized. Silence the warning by initializing the variable to an
arbitrary value.

Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
---
 drivers/gpu/drm/i915/i915_hwmon.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index a3bdd9f68a458..685663861bc0b 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -502,8 +502,11 @@ void i915_hwmon_power_max_disable(struct drm_i915_private *i915, bool *old)
 	struct i915_hwmon *hwmon = i915->hwmon;
 	u32 r;
 
-	if (!hwmon || !i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit))
+	if (!hwmon || !i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit)) {
+		/* Fix uninitialized bool variable warning */
+		*old = false;
 		return;
+	}
 
 	mutex_lock(&hwmon->hwmon_lock);
 
-- 
2.38.0