Re: [PATCH v5] pci: loongson: Workaround MIPS firmware MRRS settings

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

Hi Jiaxun,

kernel test robot noticed the following build warnings:

[auto build test WARNING on pci/next]
[also build test WARNING on pci/for-linus linus/master v6.7-rc2 next-20231120]
[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/Jiaxun-Yang/pci-loongson-Workaround-MIPS-firmware-MRRS-settings/20231120-055946
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20231119215635.52810-1-jiaxun.yang%40flygoat.com
patch subject: [PATCH v5] pci: loongson: Workaround MIPS firmware MRRS settings
config: mips-allmodconfig (https://download.01.org/0day-ci/archive/20231120/202311201537.u2ZGD7A8-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231120/202311201537.u2ZGD7A8-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/202311201537.u2ZGD7A8-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/pci/controller/pci-loongson.c:10:
   drivers/pci/controller/pci-loongson.c:122:50: error: 'loongson_mrrs_quirk_old' undeclared here (not in a function)
     122 | DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, loongson_mrrs_quirk_old);
         |                                                  ^~~~~~~~~~~~~~~~~~~~~~~
   include/linux/pci.h:2241:57: note: in definition of macro 'DECLARE_PCI_FIXUP_SECTION'
    2241 |                 = { vendor, device, class, class_shift, hook };
         |                                                         ^~~~
   drivers/pci/controller/pci-loongson.c:122:1: note: in expansion of macro 'DECLARE_PCI_FIXUP_ENABLE'
     122 | DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, loongson_mrrs_quirk_old);
         | ^~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/pci/controller/pci-loongson.c:92:13: warning: 'loongson_set_min_mrrs_quirk' defined but not used [-Wunused-function]
      92 | static void loongson_set_min_mrrs_quirk(struct pci_dev *pdev)
         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/loongson_set_min_mrrs_quirk +92 drivers/pci/controller/pci-loongson.c

    54	
    55	/* Fixup wrong class code in PCIe bridges */
    56	static void bridge_class_quirk(struct pci_dev *dev)
    57	{
    58		dev->class = PCI_CLASS_BRIDGE_PCI_NORMAL;
    59	}
    60	DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
    61				DEV_LS7A_PCIE_PORT0, bridge_class_quirk);
    62	DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
    63				DEV_LS7A_PCIE_PORT1, bridge_class_quirk);
    64	DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
    65				DEV_LS7A_PCIE_PORT2, bridge_class_quirk);
    66	
    67	static void system_bus_quirk(struct pci_dev *pdev)
    68	{
    69		/*
    70		 * The address space consumed by these devices is outside the
    71		 * resources of the host bridge.
    72		 */
    73		pdev->mmio_always_on = 1;
    74		pdev->non_compliant_bars = 1;
    75	}
    76	DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
    77				DEV_LS2K_APB, system_bus_quirk);
    78	DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
    79				DEV_LS7A_CONF, system_bus_quirk);
    80	DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
    81				DEV_LS7A_LPC, system_bus_quirk);
    82	
    83	/*
    84	 * Some Loongson PCIe ports have h/w limitations of maximum read
    85	 * request size. They can't handle anything larger than this.
    86	 * Sane firmware will set proper MRRS at boot, so we only need
    87	 * no_inc_mrrs for bridges. However, some MIPS Loongson firmware
    88	 * won't set MRRS properly, and we have to enforce maximum safe
    89	 * MRRS, which is 256 bytes.
    90	 */
    91	#ifdef CONFIG_MIPS
  > 92	static void loongson_set_min_mrrs_quirk(struct pci_dev *pdev)
    93	{
    94		struct pci_bus *bus = pdev->bus;
    95		struct pci_dev *bridge;
    96		static const struct pci_device_id bridge_devids[] = {
    97			{ PCI_VDEVICE(LOONGSON, DEV_LS2K_PCIE_PORT0) },
    98			{ PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT0) },
    99			{ PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT1) },
   100			{ PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT2) },
   101			{ PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT3) },
   102			{ PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT4) },
   103			{ PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT5) },
   104			{ PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT6) },
   105			{ 0, },
   106		};
   107	
   108		/* look for the matching bridge */
   109		while (!pci_is_root_bus(bus)) {
   110			bridge = bus->self;
   111			bus = bus->parent;
   112	
   113			if (pci_match_id(bridge_devids, bridge)) {
   114				if (pcie_get_readrq(pdev) > 256) {
   115					pci_info(pdev, "limiting MRRS to 256\n");
   116					pcie_set_readrq(pdev, 256);
   117				}
   118				break;
   119			}
   120		}
   121	}
   122	DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, loongson_mrrs_quirk_old);
   123	#endif
   124	

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