linux-kernel - Re: [PATCH] i2c: Make I2C ID tables non-mandatory for DT'ed and/or ACPI'ed devices

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]

Date:	Thu, 12 Jun 2014 09:55:21 +0200
From:	Linus Walleij <linus.walleij@...aro.org>
To:	Michael Lawnick <ml.lawnick@....de>
Cc:	Wolfram Sang <wsa@...-dreams.de>,
	Grant Likely <grant.likely@...aro.org>,
	Lee Jones <lee.jones@...aro.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>
Subject: Re: [PATCH] i2c: Make I2C ID tables non-mandatory for DT'ed and/or
 ACPI'ed devices

On Wed, Jun 4, 2014 at 8:09 AM, Michael Lawnick <ml.lawnick@....de> wrote:
> Am 03.06.2014 13:18, schrieb Linus Walleij:
>> On Mon, Jun 2, 2014 at 4:29 PM, Michael Lawnick <ml.lawnick@....de> wrote:
>>>
>>> Am 02.06.2014 14:16, schrieb Linus Walleij:
>>
>>
>>>> Is this really so useful on embedded systems?
>>>>
>>>> I was under the impression that this method was something used
>>>> on say PC desktops with temperature monitors and EEPROMs
>>>> on some I2C link on the PCB, usage entirely optional and fun
>>>> for userspace hacks.
>>>>
>>> We use it for dynamic instantiating whole subsystems with multiplexers,
>>> sensors, controllers in an embedded system. The device list is taken from
>>> an
>>> I2C eeprom which gets read on hotplug.
>>
>>
>> Does this mean that you have stored the names (strings) that are used
>> by the Linux kernel for identifying the devices into your EEPROM?
>>
>> That means that you have made the kernel-internal device driver names
>> an ABI which is unfortunate :-/
>>
>> This is one of the reasons to why we insist on device tree: OS neutral
>> hardware description.
>
> The eeprom contains a device tree that is dynamically merged.

That is a kind of way of saying "yes we made the kernel-internal
driver named an ABI" I guess?

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/