Re: [Intel-gfx] [PATCH i-g-t 1/2] drm/i915: Add support for LMEM PCIe resizable bar

kernel test robot
2022-06-16T15:41:07Z

Hi,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on drm-tip/drm-tip]

url: https://github.com/intel-lab-lkp/linux/commits/priyanka-dandamudi-intel-com/Add-support-for-LMEM-PCIe-resizable-bar/20220616-201631
base: git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: i386-randconfig-a013 (https://download.01.org/0day-ci/archive/20220616/202206162313.aYMhL5Br-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project f0e608de27b3d568000046eebf3712ab542979d6)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/0242b37c1e2e73134035a0847c34367331f16cca
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review priyanka-dandamudi-intel-com/Add-support-for-LMEM-PCIe-resizable-bar/20220616-201631
git checkout 0242b37c1e2e73134035a0847c34367331f16cca
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpu/drm/i915/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/i915/i915_driver.c:374:44: warning: result of comparison of constant 4294967296 with expression of type 'resource_size_t' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
IORESOURCE_MEM_64) && root_res->start > 0x100000000ull)
~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~
1 warning generated.

vim +374 drivers/gpu/drm/i915/i915_driver.c

354
355 #define LMEM_BAR_NUM 2
356 static void i915_resize_lmem_bar(struct drm_i915_private *i915)
357 {
358 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
359 struct pci_bus *root = pdev->bus;
360 struct resource *root_res;
361 resource_size_t rebar_size = __lmem_rebar_size(i915, LMEM_BAR_NUM);
362 u32 pci_cmd;
363 int i;
364
365 if (!rebar_size)
366 return;
367
368 /* Find out if root bus contains 64bit memory addressing */
369 while (root->parent)
370 root = root->parent;
371
372 pci_bus_for_each_resource(root, root_res, i) {
373 if (root_res && root_res->flags & (IORESOURCE_MEM |
> 374 IORESOURCE_MEM_64) && root_res->start > 0x100000000ull)
375 break;
376 }
377
378 /* pci_resize_resource will fail anyways */
379 if (!root_res) {
380 drm_info(&i915->drm, "Can't resize LMEM BAR - platform support is missing\n");
381 return;
382 }
383
384 /* First disable PCI memory decoding references */
385 pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd);
386 pci_write_config_dword(pdev, PCI_COMMAND,
387 pci_cmd & ~PCI_COMMAND_MEMORY);
388
389 __resize_bar(i915, LMEM_BAR_NUM, rebar_size);
390
391 pci_assign_unassigned_bus_resources(pdev->bus);
392 pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd);
393 }
394

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0-DAY CI Kernel Test Service