Re: [PATCH v7 5/7] nvmem: core: Rework layouts to become platform devices
From: Dan Carpenter
Date: Thu Aug 03 2023 - 06:13:15 EST
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@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230803/202308030002.DnSFOrMB-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
| Closes: https://lore.kernel.org/r/202308030002.DnSFOrMB-lkp@xxxxxxxxx/
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/
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
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 }
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