linux-kernel - Re: [PATCH v5 2/5] i2c: piix4: Depends on X86

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <24febda9-6360-459f-82d3-6fba9ed9be83@kernel.org>
Date: Tue, 10 Jun 2025 07:12:31 -0700
From: Mario Limonciello <superm1@...nel.org>
To: Huacai Chen <chenhuacai@...nel.org>,
 Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Borislav Petkov <bp@...en8.de>, Jean Delvare <jdelvare@...e.com>,
 Andi Shyti <andi.shyti@...nel.org>,
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
 Jonathan Corbet <corbet@....net>,
 Mario Limonciello <mario.limonciello@....com>,
 Yazen Ghannam <yazen.ghannam@....com>, Thomas Gleixner <tglx@...utronix.de>,
 Ingo Molnar <mingo@...hat.com>, Dave Hansen <dave.hansen@...ux.intel.com>,
 "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
 "H . Peter Anvin" <hpa@...or.com>,
 Shyam Sundar S K <Shyam-sundar.S-k@....com>,
 Hans de Goede <hdegoede@...hat.com>,
 "open list:DOCUMENTATION" <linux-doc@...r.kernel.org>,
 open list <linux-kernel@...r.kernel.org>,
 "open list:I2C/SMBUS CONTROLLER DRIVERS FOR PC" <linux-i2c@...r.kernel.org>,
 "open list:AMD PMC DRIVER" <platform-driver-x86@...r.kernel.org>,
 Ingo Molnar <mingo@...nel.org>, linux-mips@...r.kernel.org,
 loongarch@...ts.linux.dev
Subject: Re: [PATCH v5 2/5] i2c: piix4: Depends on X86

On 6/10/2025 2:24 AM, Huacai Chen wrote:
> On Tue, Jun 10, 2025 at 5:16 PM Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
>>
>> Hi Mario,
>>
>> CC mips, loongarch
>>
>> On Wed, 23 Apr 2025 at 01:49, Mario Limonciello <superm1@...nel.org> wrote:
>>> From: Mario Limonciello <mario.limonciello@....com>
>>>
>>> PIIX4 and compatible controllers are only for X86. As some headers are
>>> being moved into x86 specific headers PIIX4 won't compile on non-x86.
>>>
>>> Suggested-by: Ingo Molnar <mingo@...nel.org>
>>> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
>>
>> Thanks for your patch, which is now commit 7e173eb82ae97175
>> ("i2c: piix4: Make CONFIG_I2C_PIIX4 dependent on CONFIG_X86")
>> in v6.16-rc1.
>>
>>> --- a/drivers/i2c/busses/Kconfig
>>> +++ b/drivers/i2c/busses/Kconfig
>>> @@ -200,7 +200,7 @@ config I2C_ISMT
>>>
>>>   config I2C_PIIX4
>>>          tristate "Intel PIIX4 and compatible (ATI/AMD/Serverworks/Broadcom/SMSC)"
>>> -       depends on PCI && HAS_IOPORT
>>> +       depends on PCI && HAS_IOPORT && X86
>>
>> Are you sure this south-bridge is not used on non-x86 platforms?
>> It is enabled in several non-x86 defconfigs:
>>
>>      arch/loongarch/configs/loongson3_defconfig:CONFIG_I2C_PIIX4=y
>>      arch/mips/configs/ip27_defconfig:CONFIG_I2C_PIIX4=m
>>      arch/mips/configs/loongson2k_defconfig:CONFIG_I2C_PIIX4=y
>>      arch/mips/configs/loongson3_defconfig:CONFIG_I2C_PIIX4=y
>>
>> The loongarch and loongson entries are probably bogus, but I wouldn't
>> be surprised if the SGI Onyx and Origin do use Intel south-bridges.
> Loongson can use AMD SB700/SB800 south bridges, which have I2C_PIIX4.

Well we could revert this patch, but it's going to be a compile failure 
because of 624b0d5696a89b138408d385899dd35372db324b and other patches 
that go on top of that.

My current leaning is we make a dummy fch.h header for these archs with 
#defines for 0.

Any thoughts?

> 
> Huacai
> 
>>
>>>          select I2C_SMBUS
>>>          help
>>>            If you say yes to this option, support will be included for the Intel
>>
>> Gr{oetje,eeting}s,
>>
>>                          Geert
>>
>> --
>> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org
>>
>> In personal conversations with technical people, I call myself a hacker. But
>> when I'm talking to journalists I just say "programmer" or something like that.
>>                                  -- Linus Torvalds
>>