Re: [Intel-gfx] [PATCH v4 1/2] drm/i915: Add support for LMEM PCIe resizable bar

kernel test robot
2022-07-10T19:51:28Z

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/20220711-014151
base: git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: i386-randconfig-a004 (https://download.01.org/0day-ci/archive/20220711/202207110323.aQxXZ1kk-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 6ce63e267aab79ca87bf63453d34dd3909ab978d)
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/fb47ead5e629b3aaaa718d85fb2fb960e77ebe61
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/20220711-014151
git checkout fb47ead5e629b3aaaa718d85fb2fb960e77ebe61
# 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/gt/intel_region_lmem.c:70:44: 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 +70 drivers/gpu/drm/i915/gt/intel_region_lmem.c

46
47 #define LMEM_BAR_NUM 2
48 static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t lmem_size)
49 {
50 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
51 struct pci_bus *root = pdev->bus;
52 struct resource *root_res;
53 resource_size_t rebar_size;
54 u32 pci_cmd;
55 int i;
56
57 rebar_size = roundup_pow_of_two(pci_resource_len(pdev, LMEM_BAR_NUM));
58
59 if (rebar_size != roundup_pow_of_two(lmem_size))
60 rebar_size = lmem_size;
61 else
62 return;
63
64 /* Find out if root bus contains 64bit memory addressing */
65 while (root->parent)
66 root = root->parent;
67
68 pci_bus_for_each_resource(root, root_res, i) {
69 if (root_res && root_res->flags & (IORESOURCE_MEM |
> 70 IORESOURCE_MEM_64) && root_res->start > 0x100000000ull)
71 break;
72 }
73
74 /* pci_resize_resource will fail anyways */
75 if (!root_res) {
76 drm_info(&i915->drm, "Can't resize LMEM BAR - platform support is missing\n");
77 return;
78 }
79
80 /* First disable PCI memory decoding references */
81 pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd);
82 pci_write_config_dword(pdev, PCI_COMMAND,
83 pci_cmd & ~PCI_COMMAND_MEMORY);
84
85 _resize_bar(i915, LMEM_BAR_NUM, rebar_size);
86
87 pci_assign_unassigned_bus_resources(pdev->bus);
88 pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd);
89 }
90

--
0-DAY CI Kernel Test Service