Re: [PATCH v9 4/4] irqchip/irq-loongarch-ir:Add Redirect irqchip support

Re: [PATCH v9 4/4] irqchip/irq-loongarch-ir:Add Redirect irqchip support

[kernel test robot]

Hi Tianyang,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tip/irq/core]
[also build test WARNING on linus/master v6.19-rc7 next-20260129]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Tianyang-Zhang/Docs-LoongArch-Add-Advanced-Extended-Redirect-IRQ-model-description/20260130-110249
base:   tip/irq/core
patch link:    https://lore.kernel.org/r/20260130025941.2140582-5-zhangtianyang%40loongson.cn
patch subject: [PATCH v9 4/4] irqchip/irq-loongarch-ir:Add Redirect irqchip support
config: loongarch-allnoconfig (https://download.01.org/0day-ci/archive/20260130/202601301601.EonMu52D-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9b8addffa70cee5b2acc5454712d9cf78ce45710)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260130/202601301601.EonMu52D-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/202601301601.EonMu52D-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/irqchip/irq-loongarch-ir.c:203:6: warning: variable 'order' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
     203 |         if (nr_irqs > 1) {
         |             ^~~~~~~~~~~
   drivers/irqchip/irq-loongarch-ir.c:211:19: note: uninitialized use occurs here
     211 |                                         IRD_ENTRIES, order);
         |                                                      ^~~~~
   drivers/irqchip/irq-loongarch-ir.c:203:2: note: remove the 'if' if its condition is always true
     203 |         if (nr_irqs > 1) {
         |         ^~~~~~~~~~~~~~~~
   drivers/irqchip/irq-loongarch-ir.c:201:27: note: initialize the variable 'order' to silence this warning
     201 |         unsigned int index, order;
         |                                  ^
         |                                   = 0
   1 warning generated.


vim +203 drivers/irqchip/irq-loongarch-ir.c

   197	
   198	static int redirect_table_alloc(int node, u32 nr_irqs)
   199	{
   200		struct redirect_table *ird_table = &irde_descs[node].ird_table;
   201		unsigned int index, order;
   202	
 > 203		if (nr_irqs > 1) {
   204			nr_irqs = __roundup_pow_of_two(nr_irqs);
   205			order = ilog2(nr_irqs);
   206		}
   207	
   208		guard(raw_spinlock_irqsave)(&ird_table->lock);
   209	
   210		index = bitmap_find_free_region(ird_table->bitmap,
   211						IRD_ENTRIES, order);
   212		if (index < 0) {
   213			pr_err("No redirect entry to use\n");
   214			return -ENOMEM;
   215		}
   216	
   217		return index;
   218	}
   219	

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