linux-kernel - Re: MMC: Make the configuration memory resource optional

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: <aec7e5c30907290551y77edc6d7qb7b3d787215c2b4@mail.gmail.com>
Date:	Wed, 29 Jul 2009 21:51:30 +0900
From:	Magnus Damm <magnus.damm@...il.com>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc:	Ian Molton <ian@...menth.co.uk>,
	Guennadi Liakhovetski <g.liakhovetski@....de>,
	linux-kernel@...r.kernel.org, Pierre Ossman <drzeus@...eus.cx>,
	Magnus Damm <damm@...nsource.se>
Subject: Re: MMC: Make the configuration memory resource optional

On Wed, Jul 29, 2009 at 9:42 PM, Mark
Brown<broonie@...nsource.wolfsonmicro.com> wrote:
> On Wed, Jul 29, 2009 at 09:27:54PM +0900, Magnus Damm wrote:
>> On Wed, Jul 29, 2009 at 8:58 PM, Mark
>> Brown<broonie@...nsource.wolfsonmicro.com> wrote:
>
>> > While it's true that this doesn't bother SoCs the fact that most clock
>> > API implementations don't allow any off-chip drivers to register clocks
>> > renders the clock API essentially unusable for fairly large parts of the
>
>> Yeah, clocks outside the SoC are not well supported today. From what
>> I've seen, most embedded boards come with external chips for cameras,
>> audio codecs and/or phy devices. These devices often get their clocks
>> from the main SoC. Allowing the drivers for such chips to use the
>> clock framework to register clocks for internal divisors would allow
>> driver writers to write better code which in turn would make life
>> easier for most people hacking on embedded kernels.
>
> That's not actually abundantly clear for the audio stuff, or rather the
> audio stuff would like additional features like constraint based
> configuration.

Without knowing too much about this, wouldn't camera sensors want
similar features?

>> The problem with the clock framework API is that the data structures
>> varies depending on implementation. So the ops callback structure on
>> SuperH is different compared to ARM. I suspect that adding generic
>> clocklib support across the architectures will take quite a bit of
>> time to implement propely.
>
> Indeed.  It's actually much worse than you say, each individual ARM
> architecture has its own clock API implementation of varying quality and
> of course there are architectures that don't do the clock API at all.

Yeah. This is exactly why I don't want to block on the clocklib implementation.

Cheers,

/ magnus
--
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/