Hi Dan, On Tue, Jul 7, 2020 at 9:27 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > Hi Jim, > > url: https://github.com/0day-ci/linux/commits/Jim-Quinlan/PCI-brcmstb-enable-PCIe-for-STB-chips/20200702-053156 > base: https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next > config: arm-randconfig-m031-20200701 (attached as .config) > compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > smatch warnings: > drivers/of/address.c:1012 of_dma_get_range() warn: passing zero to 'ERR_PTR' > > # https://github.com/0day-ci/linux/commit/0c50b6db383883854419f10df0d79b663433f121 > git remote add linux-review https://github.com/0day-ci/linux > git remote update linux-review > git checkout 0c50b6db383883854419f10df0d79b663433f121 > vim +/ERR_PTR +1012 drivers/of/address.c > > 18308c94723e16 Grygorii Strashko 2014-04-24 955 /** > 0c50b6db383883 Jim Quinlan 2020-07-01 956 * of_dma_get_range - Get DMA range info and put it into a map array > 18308c94723e16 Grygorii Strashko 2014-04-24 957 * @np: device node to get DMA range info > 18308c94723e16 Grygorii Strashko 2014-04-24 958 * > 18308c94723e16 Grygorii Strashko 2014-04-24 959 * Look in bottom up direction for the first "dma-ranges" property > 0c50b6db383883 Jim Quinlan 2020-07-01 960 * and parse it. Put the information into a DMA offset map array. > 0c50b6db383883 Jim Quinlan 2020-07-01 961 * > 18308c94723e16 Grygorii Strashko 2014-04-24 962 * dma-ranges format: > 18308c94723e16 Grygorii Strashko 2014-04-24 963 * DMA addr (dma_addr) : naddr cells > 18308c94723e16 Grygorii Strashko 2014-04-24 964 * CPU addr (phys_addr_t) : pna cells > 18308c94723e16 Grygorii Strashko 2014-04-24 965 * size : nsize cells > 18308c94723e16 Grygorii Strashko 2014-04-24 966 * > 0c50b6db383883 Jim Quinlan 2020-07-01 967 * It returns -ENODEV if "dma-ranges" property was not found for this > 0c50b6db383883 Jim Quinlan 2020-07-01 968 * device in the DT. > 18308c94723e16 Grygorii Strashko 2014-04-24 969 */ > 0c50b6db383883 Jim Quinlan 2020-07-01 970 const struct bus_dma_region *of_dma_get_range(struct device_node *np) > 18308c94723e16 Grygorii Strashko 2014-04-24 971 { > 0c50b6db383883 Jim Quinlan 2020-07-01 972 const struct bus_dma_region *map = NULL; > 18308c94723e16 Grygorii Strashko 2014-04-24 973 struct device_node *node = of_node_get(np); > 0c50b6db383883 Jim Quinlan 2020-07-01 974 struct of_range_parser parser; > 18308c94723e16 Grygorii Strashko 2014-04-24 975 const __be32 *ranges = NULL; > 951d48855d86e7 Robin Murphy 2019-07-03 976 bool found_dma_ranges = false; > 7a8b64d17e3581 Rob Herring 2020-02-06 977 struct of_range range; > 0c50b6db383883 Jim Quinlan 2020-07-01 978 int len, num_ranges = 0; > 0c50b6db383883 Jim Quinlan 2020-07-01 979 int ret = 0; > 18308c94723e16 Grygorii Strashko 2014-04-24 980 > 951d48855d86e7 Robin Murphy 2019-07-03 981 while (node) { > 18308c94723e16 Grygorii Strashko 2014-04-24 982 ranges = of_get_property(node, "dma-ranges", &len); > 18308c94723e16 Grygorii Strashko 2014-04-24 983 > 18308c94723e16 Grygorii Strashko 2014-04-24 984 /* Ignore empty ranges, they imply no translation required */ > 18308c94723e16 Grygorii Strashko 2014-04-24 985 if (ranges && len > 0) > 18308c94723e16 Grygorii Strashko 2014-04-24 986 break; > 18308c94723e16 Grygorii Strashko 2014-04-24 987 > 951d48855d86e7 Robin Murphy 2019-07-03 988 /* Once we find 'dma-ranges', then a missing one is an error */ > 951d48855d86e7 Robin Murphy 2019-07-03 989 if (found_dma_ranges && !ranges) { > 951d48855d86e7 Robin Murphy 2019-07-03 990 ret = -ENODEV; > 951d48855d86e7 Robin Murphy 2019-07-03 991 goto out; > 18308c94723e16 Grygorii Strashko 2014-04-24 992 } > 951d48855d86e7 Robin Murphy 2019-07-03 993 found_dma_ranges = true; > 18308c94723e16 Grygorii Strashko 2014-04-24 994 > 951d48855d86e7 Robin Murphy 2019-07-03 995 node = of_get_next_dma_parent(node); > 951d48855d86e7 Robin Murphy 2019-07-03 996 } > 951d48855d86e7 Robin Murphy 2019-07-03 997 > 951d48855d86e7 Robin Murphy 2019-07-03 998 if (!node || !ranges) { > 0d638a07d3a1e9 Rob Herring 2017-06-01 999 pr_debug("no dma-ranges found for node(%pOF)\n", np); > 18308c94723e16 Grygorii Strashko 2014-04-24 1000 ret = -ENODEV; > 18308c94723e16 Grygorii Strashko 2014-04-24 1001 goto out; > 18308c94723e16 Grygorii Strashko 2014-04-24 1002 } > 18308c94723e16 Grygorii Strashko 2014-04-24 1003 > 7a8b64d17e3581 Rob Herring 2020-02-06 1004 of_dma_range_parser_init(&parser, node); > 7a8b64d17e3581 Rob Herring 2020-02-06 1005 > 0c50b6db383883 Jim Quinlan 2020-07-01 1006 for_each_of_range(&parser, &range) > 0c50b6db383883 Jim Quinlan 2020-07-01 1007 num_ranges++; > 18308c94723e16 Grygorii Strashko 2014-04-24 1008 > 0c50b6db383883 Jim Quinlan 2020-07-01 1009 map = dma_create_offset_map(node, num_ranges); > ^^^ > If this fails then "ret" is zero so the function returns NULL instead of > an error pointer. I'm not sure I see what is wrong with this; perhaps my usage is unorthodox and has triggered this warning. The return of map = of_dma_get_range(....); can mean one of three things: 1. Failure, ret = PTR_ERR(map) gives the errno. 2. Success, map is a valid memory pointer /* occurs when there are "dma-ranges" */ 3. Success, map is the NULL pointer and ret = PTR_ERR(map) yields 0. /* occurs when there are no "dma-ranges" */ After calling this function I do this ret = IS_ERR(map) ? PTR_ERR(map) : 0; which will be replaced in the next version with this: ret = PTR_ERR_OR_ZERO(map); If ret == 0 I do the assignment dev->dma_range_map = map; which is exactly what I want. Please advise if action on my part is still required. Thanks, Jim Quinlan Broadcom STB > > 18308c94723e16 Grygorii Strashko 2014-04-24 1010 out: > 18308c94723e16 Grygorii Strashko 2014-04-24 1011 of_node_put(node); > 0c50b6db383883 Jim Quinlan 2020-07-01 @1012 return map ? map : ERR_PTR(ret); > 92ea637edea36e Santosh Shilimkar 2014-04-24 1014 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
