Re: [PATCH v7 2/2] PCI: dwc: Validate max-link-speed property

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

Hi Hans,

kernel test robot noticed the following build errors:

[auto build test ERROR on c23719abc3308df7ed3ad35650ad211fb2d2003d]

url:    https://github.com/intel-lab-lkp/linux/commits/Hans-Zhang/PCI-of-Remove-max-link-speed-generation-validation/20260308-223128
base:   c23719abc3308df7ed3ad35650ad211fb2d2003d
patch link:    https://lore.kernel.org/r/20260308142629.75392-3-18255117159%40163.com
patch subject: [PATCH v7 2/2] PCI: dwc: Validate max-link-speed property
config: i386-randconfig-004-20260308 (https://download.01.org/0day-ci/archive/20260309/202603092301.uROFb9mn-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260309/202603092301.uROFb9mn-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/202603092301.uROFb9mn-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/pci/controller/dwc/pcie-designware.c:128:19: error: invalid application of 'sizeof' to an incomplete type 'const unsigned char[]'
     128 |             max_speed >= ARRAY_SIZE(pcie_link_speed) ||
         |                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/array_size.h:11:32: note: expanded from macro 'ARRAY_SIZE'
      11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
         |                                ^~~~~
   drivers/pci/controller/dwc/pcie-designware.c:255:9: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
     255 |         return PCI_FIND_NEXT_CAP(dw_pcie_read_cfg, PCI_CAPABILITY_LIST, cap,
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     256 |                                  NULL, pci);
         |                                  ~~~~~~~~~~
   drivers/pci/controller/dwc/../../pci.h:159:5: note: expanded from macro 'PCI_FIND_NEXT_CAP'
     159 |                                 *(u8 *)prev_ptr = __prev_pos;           \
         |                                 ^~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/pcie-designware.c:255:9: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
   drivers/pci/controller/dwc/../../pci.h:159:5: note: expanded from macro 'PCI_FIND_NEXT_CAP'
     159 |                                 *(u8 *)prev_ptr = __prev_pos;           \
         |                                 ^
   drivers/pci/controller/dwc/pcie-designware.c:262:9: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
     262 |         return PCI_FIND_NEXT_EXT_CAP(dw_pcie_read_cfg, 0, cap, NULL, pci);
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/pcie-designware.c:262:9: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^
   drivers/pci/controller/dwc/pcie-designware.c:329:17: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
     329 |         while ((vsec = PCI_FIND_NEXT_EXT_CAP(dw_pcie_read_cfg, vsec,
         |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     330 |                                              PCI_EXT_CAP_ID_VNDR, NULL, pci))) {
         |                                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^~~~~~~~~~~~~~~~
   drivers/pci/controller/dwc/pcie-designware.c:329:17: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
   drivers/pci/controller/dwc/../../pci.h:207:5: note: expanded from macro 'PCI_FIND_NEXT_EXT_CAP'
     207 |                                 *(u16 *)prev_ptr = __prev_pos;          \
         |                                 ^
   3 warnings and 1 error generated.


vim +128 drivers/pci/controller/dwc/pcie-designware.c

   112	
   113	static void dw_pcie_get_link_speed(struct dw_pcie *pci)
   114	{
   115		struct device_node *np = dev_of_node(pci->dev);
   116		int max_speed;
   117	
   118		max_speed = of_pci_get_max_link_speed(np);
   119		if (max_speed < 0) {
   120			dev_warn(pci->dev,
   121				 "Failed to get max-link-speed, using default (Gen1)\n");
   122			pci->max_link_speed = 1;
   123			return;
   124		}
   125	
   126		/* Validate against known speeds in pcie_link_speed */
   127		if (max_speed == 0 ||
 > 128		    max_speed >= ARRAY_SIZE(pcie_link_speed) ||
   129		    pcie_link_speed[max_speed] == PCI_SPEED_UNKNOWN) {
   130			dev_warn(pci->dev,
   131				 "Invalid max-link-speed %d, using default (Gen1)\n",
   132				 max_speed);
   133			pci->max_link_speed = 1;
   134			return;
   135		}
   136	
   137		pci->max_link_speed = max_speed;
   138	}
   139	

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