Re: drivers/platform/x86/dell/dell-smbios-smm.c:27:35: warning: unused variable 'dell_device_table'
From: Hans de Goede
Date: Tue Jun 08 2021 - 04:36:35 EST
<replaced Mario's old Dell email address which one which works>
Hi all,
On 6/8/21 12:41 AM, kernel test robot wrote:
> Hi Mario,
>
> FYI, the error/warning still remains.
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 614124bea77e452aa6df7a8714e8bc820b489922
> commit: f1e1ea516721d1ea0b21327ff9e6cb2c2bb86e28 platform/x86: Move all dell drivers to their own subdirectory
> date: 4 months ago
> config: x86_64-randconfig-r023-20210608 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project ae973380c5f6be77ce395022be40350942260be9)
> 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
> # install x86_64 cross compiling tool for clang build
> # apt-get install binutils-x86-64-linux-gnu
> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f1e1ea516721d1ea0b21327ff9e6cb2c2bb86e28
> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout f1e1ea516721d1ea0b21327ff9e6cb2c2bb86e28
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>):
>
>>> drivers/platform/x86/dell/dell-smbios-smm.c:27:35: warning: unused variable 'dell_device_table' [-Wunused-const-variable]
> static const struct dmi_system_id dell_device_table[] __initconst = {
> ^
> 1 warning generated.
>
>
> vim +/dell_device_table +27 drivers/platform/x86/dell/dell-smbios-smm.c
>
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 26
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 @27 static const struct dmi_system_id dell_device_table[] __initconst = {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 28 {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 29 .ident = "Dell laptop",
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 30 .matches = {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 31 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 32 DMI_MATCH(DMI_CHASSIS_TYPE, "8"),
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 33 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 34 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 35 {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 36 .matches = {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 37 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 38 DMI_MATCH(DMI_CHASSIS_TYPE, "9"), /*Laptop*/
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 39 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 40 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 41 {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 42 .matches = {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 43 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 44 DMI_MATCH(DMI_CHASSIS_TYPE, "10"), /*Notebook*/
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 45 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 46 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 47 {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 48 .ident = "Dell Computer Corporation",
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 49 .matches = {
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 50 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 51 DMI_MATCH(DMI_CHASSIS_TYPE, "8"),
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 52 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 53 },
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 54 { }
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 55 };
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 56 MODULE_DEVICE_TABLE(dmi, dell_device_table);
Note the MODULE_DEVICE_TABLE() here; and I checked and CONFIG_DMI=y in the config used
here as expected, so this seems like a false-positive warnings, with that said I was
still a bit surprised about the presence of this table since dell-smbios is depended
on by dell-laptop and that has this same table + same extra entries for chassis-type
30, 31 and 32.
Since dell-laptop will already auto-load based on the DMI table in there (which also is
more complete) and since dell-laptop will then bring in the dell-smbios module, the only
scenario I can think of where this DMI table inside dell-smbios-smm.c is useful is if
users have the dell-laptop module disabled and they want to use the sysfs interface
offered by dell-smbios-smm.c. But that seems such a corner case that I believe it
would be fair to tell users to do a modprobe themselves in this case ?
This would allow removing the dupplicate table from dell-smbios-smm.c, which would be
a good thing, because as the differences between the 2 copies which have accumulated
over time show, having the same table in 2 places seems like a bad idea.
Mario, even though you are no longer at Dell, I would still very much appreciate your
thoughts on this.
Regards,
Hans
> 549b4930f05765 drivers/platform/x86/dell-smbios-smm.c Mario Limonciello 2017-11-01 57
>
> :::::: The code at line 27 was first introduced by commit
> :::::: 549b4930f057658dc50d8010e66219233119a4d8 platform/x86: dell-smbios: Introduce dispatcher for SMM calls
>
> :::::: TO: Mario Limonciello <mario.limonciello@xxxxxxxx>
> :::::: CC: Darren Hart (VMware) <dvhart@xxxxxxxxxxxxx>
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
>