[v2,3/3] wifi: ath10k: only load compatible DT cal data

From: Edward Chow <equu@openmail.cc>

ath10k might also be sensitive to the issue reported on
https://github.com/openwrt/openwrt/pull/11345 , loading calibration
data from a device tree node declared incompatible.

ath10k will first check whether the device tree node is compatible
with it, using the functionality introduced with the first patch of
this series, ("PCI: of: Match pci devices or drivers against OF DT
nodes") and only proceed loading calibration data from compatible node.

Signed-off-by: Edward Chow <equu@openmail.cc>
---
 drivers/net/wireless/ath/ath10k/core.c | 28 ++++++++++++++++++++++++++
 drivers/net/wireless/ath/ath10k/pci.c  |  2 +-
 drivers/net/wireless/ath/ath10k/pci.h  |  2 ++
 3 files changed, 31 insertions(+), 1 deletion(-)

Hi,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on helgaas-pci/next]
[also build test WARNING on helgaas-pci/for-linus wireless-next/main wireless/main linus/master v6.2-rc6 next-20230202]
[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/equu-openmail-cc/wifi-ath9k-stop-loading-incompatible-DT-cal-data/20230202-131914
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
patch link:    https://lore.kernel.org/r/20230202041823.2879262-4-equu%40openmail.cc
patch subject: [PATCH v2 3/3] wifi: ath10k: only load compatible DT cal data
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230202/202302021511.hIXEXftH-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
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/d3f328c8809b6349090ad2a2ee78250d657edb58
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review equu-openmail-cc/wifi-ath9k-stop-loading-incompatible-DT-cal-data/20230202-131914
        git checkout d3f328c8809b6349090ad2a2ee78250d657edb58
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/net/

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/net/wireless/ath/ath10k/core.c: In function 'ath10k_download_cal_nvmem':
   drivers/net/wireless/ath/ath10k/core.c:1985:15: error: implicit declaration of function 'of_pci_node_match_device' [-Werror=implicit-function-declaration]
    1985 |              !of_pci_node_match_device(ar->dev->of_node,
         |               ^~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/net/wireless/ath/ath10k/core.c:1987:24: warning: returning 'void *' from a function with return type 'int' makes integer from pointer without a cast [-Wint-conversion]
    1987 |                 return ERR_PTR(-ENOENT);
         |                        ^~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +1987 drivers/net/wireless/ath/ath10k/core.c

  1954	
  1955	static int ath10k_download_cal_nvmem(struct ath10k *ar, const char *cell_name)
  1956	{
  1957		struct nvmem_cell *cell;
  1958		void *buf;
  1959		size_t len;
  1960		int ret;
  1961	
  1962		/* devm_nvmem_cell_get() will get a cell first from the OF
  1963		 * DT node representing the given device with nvmem-cell-name
  1964		 * "calibration", and from the global lookup table as a fallback,
  1965		 * and an ath9k device could be either a pci one or a platform one.
  1966		 *
  1967		 * If the OF DT node is not compatible with the real device, the
  1968		 * calibration data got from the node should not be applied.
  1969		 *
  1970		 * dev_is_pci(ar->dev) && ( no OF node || caldata not from node
  1971		 * || not compatible ) -> do not use caldata .
  1972		 *
  1973		 * !dev_is_pci(ar->dev) -> always use caldata .
  1974		 *
  1975		 * The judgement for compatibility differs with ath9k for many
  1976		 * DT using "qcom,ath10k" as compatibility string.
  1977		 */
  1978		if (dev_is_pci(ar->dev) &&
  1979		    (!ar->dev->of_node ||
  1980		     (of_property_match_string(ar->dev->of_node,
  1981					       "nvmem-cell-names",
  1982					       cell_name) < 0) ||
  1983		     !of_device_is_compatible(ar->dev->of_node,
  1984					      "qcom,ath10k") ||
  1985		     !of_pci_node_match_device(ar->dev->of_node,
  1986					       &ath10k_pci_driver)))
> 1987			return ERR_PTR(-ENOENT);
  1988	
  1989		cell = devm_nvmem_cell_get(ar->dev, cell_name);
  1990		if (IS_ERR(cell)) {
  1991			ret = PTR_ERR(cell);
  1992			return ret;
  1993		}
  1994	
  1995		buf = nvmem_cell_read(cell, &len);
  1996		if (IS_ERR(buf))
  1997			return PTR_ERR(buf);
  1998	
  1999		if (ar->hw_params.cal_data_len != len) {
  2000			kfree(buf);
  2001			ath10k_warn(ar, "invalid calibration data length in nvmem-cell '%s': %zu != %u\n",
  2002				    cell_name, len, ar->hw_params.cal_data_len);
  2003			return -EMSGSIZE;
  2004		}
  2005	
  2006		ret = ath10k_download_board_data(ar, buf, len);
  2007		kfree(buf);
  2008		if (ret)
  2009			ath10k_warn(ar, "failed to download calibration data from nvmem-cell '%s': %d\n",
  2010				    cell_name, ret);
  2011	
  2012		return ret;
  2013	}
  2014