Messages in this thread | | | Date | Fri, 4 Aug 2023 17:46:25 +0200 | From | Miquel Raynal <> | Subject | Re: [PATCH v7 5/7] nvmem: core: Rework layouts to become platform devices |
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Hi again Dan,
miquel.raynal@bootlin.com wrote on Fri, 4 Aug 2023 17:39:03 +0200:
> Hi Dan, > > dan.carpenter@linaro.org wrote on Thu, 3 Aug 2023 13:13:04 +0300: > > > Hi Miquel, > > > > kernel test robot noticed the following build warnings: > > > > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > > > url: https://github.com/intel-lab-lkp/linux/commits/Miquel-Raynal/nvmem-core-Create-all-cells-before-adding-the-nvmem-device/20230802-022331 > > base: char-misc/char-misc-testing > > patch link: https://lore.kernel.org/r/20230801182132.1058707-6-miquel.raynal%40bootlin.com > > patch subject: [PATCH v7 5/7] nvmem: core: Rework layouts to become platform devices > > config: x86_64-randconfig-m001-20230730 (https://download.01.org/0day-ci/archive/20230803/202308030002.DnSFOrMB-lkp@intel.com/config) > > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 > > reproduce: (https://download.01.org/0day-ci/archive/20230803/202308030002.DnSFOrMB-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), > > (Nice addition, a lot of newcomers would always add these tags > otherwise.) > > > kindly add following tags > > | Reported-by: kernel test robot <lkp@intel.com> > > | Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > | Closes: https://lore.kernel.org/r/202308030002.DnSFOrMB-lkp@intel.com/ > > > > New smatch warnings: > > drivers/nvmem/core.c:1003 nvmem_register() warn: 'layout_np' is an error pointer or valid > > drivers/nvmem/core.c:2130 nvmem_try_loading_layout_driver() warn: 'layout_np' is an error pointer or valid > > > > Old smatch warnings: > > drivers/nvmem/core.c:761 nvmem_add_cells_from_fixed_layout() warn: 'layout_np' is an error pointer or valid > > drivers/nvmem/core.c:802 nvmem_layout_get() warn: 'layout_np' is an error pointer or valid > > > > vim +/layout_np +1003 drivers/nvmem/core.c > > > > 266570f496b90d Michael Walle 2023-04-04 1000 > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1001 /* Populate layouts as devices */ > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1002 layout_np = of_nvmem_layout_get_container(nvmem); > > 00d059fd6702f0 Miquel Raynal 2023-08-01 @1003 if (layout_np) { > > > > So, ugh, of_nvmem_layout_get_container() return NULL on error or error > > pointer if either CONFIG_NVMEM or CONFIG_OF is turned off. I feel like > > that's a mistake. Normally when a function returns both error pointers > > and NULL then the NULL means the feature is disabled and the error > > pointers mean there was an error. Here it is the opposite. > > > > I have written a blog about this: > > https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/ > > Nice (besides the huge spider which stared at me unexpectedly :-) ) > > > At first I thought that this was to do with CONFIG_COMPILE_TEST but > > actually that is disabled. The issue here is that CONFIG_OF is turned > > off. So this is a genuine bug, we're compiling a module which will > > always crash. > > > > So I guess the fix is easy that this should return NULL if either > > CONFIG_NVMEM or CONFIG_OF is turned off. That was a long explanation > > which is no longer required now that it's not a COMPILE_TEST issue. :P > > I wanted to disable CONFIG_OF to make the test, I totally forget, I'll > handle this case and return NULL when this happens.
Actually of_nvmem_layout_get_container() already returns NULL if CONFIG_OF is not defined. This helper returns either a valid pointer of NULL. Where can it return an error pointer?
> However I don't understand why you mention CONFIG_NVMEM, because if it > is not defined, this file will not compile at all? > > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1004 rval = of_platform_populate(nvmem->dev.of_node, NULL, NULL, NULL); > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1005 if (rval) > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1006 goto err_remove_cells; > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1007 of_node_put(layout_np); > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1008 } > > 00d059fd6702f0 Miquel Raynal 2023-08-01 1009 > > 25c9b5d3aa24a0 Miquel Raynal 2023-08-01 1010 mutex_lock(&nvmem_devices_mutex); > > 25c9b5d3aa24a0 Miquel Raynal 2023-08-01 1011 list_add_tail(&nvmem->node, &nvmem_devices_list); > > 25c9b5d3aa24a0 Miquel Raynal 2023-08-01 1012 mutex_unlock(&nvmem_devices_mutex); > > 25c9b5d3aa24a0 Miquel Raynal 2023-08-01 1013 > > f4853e1c321edb Bartosz Golaszewski 2019-02-15 1014 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem); > > bee1138bea15a6 Bartosz Golaszewski 2018-09-21 1015 > > eace75cfdcf7d9 Srinivas Kandagatla 2015-07-27 1016 return nvmem; > > 3360acdf839170 Johan Hovold 2017-06-09 1017 > > b985f4cba6dbb3 Bartosz Golaszewski 2018-09-21 1018 err_remove_cells: > > b985f4cba6dbb3 Bartosz Golaszewski 2018-09-21 1019 nvmem_device_remove_all_cells(nvmem); > > fa72d847d68d78 Bartosz Golaszewski 2018-09-21 1020 if (config->compat) > > ae0c2d725512f3 Srinivas Kandagatla 2019-04-16 1021 nvmem_sysfs_remove_compat(nvmem, config); > > 3360acdf839170 Johan Hovold 2017-06-09 1022 err_put_device: > > 3360acdf839170 Johan Hovold 2017-06-09 1023 put_device(&nvmem->dev); > > 3360acdf839170 Johan Hovold 2017-06-09 1024 > > b6c217ab9be689 Andrew Lunn 2016-02-26 1025 return ERR_PTR(rval); > > eace75cfdcf7d9 Srinivas Kandagatla 2015-07-27 1026 } > > > > > Thanks, > Miquèl
Thanks, Miquèl
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