drivers/gpu/drm/nouveau/nvkm/subdev/fb/gb202.c:17:37: warning: result of comparison of constant 4503599627370495 with expression of type 'dma_addr_t' (aka 'unsigned int') is always false

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   704340f1cd0dcef829eb62f5b48ae95a2ce17bdf
commit: 31d3354f42c0da34415164a1f621a195caa1f1bc drm/nouveau: verify that hardware supports the flush page address
date:   10 months ago
config: i386-randconfig-r062-20260914 (https://download.01.org/0day-ci/archive/20260914/202609141504.5flfpx8O-lkp@intel.com/config)
compiler: clang version 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260914/202609141504.5flfpx8O-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
| Fixes: 31d3354f42c0 ("drm/nouveau: verify that hardware supports the flush page address")
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609141504.5flfpx8O-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/nouveau/nvkm/subdev/fb/gb202.c:17:37: warning: result of comparison of constant 4503599627370495 with expression of type 'dma_addr_t' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
      17 |         WARN_ON(fb->sysmem.flush_page_addr > DMA_BIT_MASK(52));
         |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
   include/asm-generic/bug.h:123:25: note: expanded from macro 'WARN_ON'
     123 |         int __ret_warn_on = !!(condition);                              \
         |                                ^~~~~~~~~
   1 warning generated.


vim +17 drivers/gpu/drm/nouveau/nvkm/subdev/fb/gb202.c

     9	
    10	static void
    11	gb202_fb_sysmem_flush_page_init(struct nvkm_fb *fb)
    12	{
    13		struct nvkm_device *device = fb->subdev.device;
    14		const u64 addr = fb->sysmem.flush_page_addr;
    15	
    16		// Ensure that the address is within hardware limits
  > 17		WARN_ON(fb->sysmem.flush_page_addr > DMA_BIT_MASK(52));
    18	
    19		nvkm_wr32(device, NV_PFB_FBHUB0_PCIE_FLUSH_SYSMEM_ADDR_HI, upper_32_bits(addr));
    20		nvkm_wr32(device, NV_PFB_FBHUB0_PCIE_FLUSH_SYSMEM_ADDR_LO, lower_32_bits(addr));
    21	}
    22	

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