linux-kernel - Re: [PATCH/RFC] dmaengine: add a slave parameter to __dma_request

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: <Pine.LNX.4.64.1203301236330.24548@axis700.grange>
Date:	Fri, 30 Mar 2012 12:40:12 +0200 (CEST)
From:	Guennadi Liakhovetski <g.liakhovetski@....de>
To:	Russell King - ARM Linux <linux@....linux.org.uk>
cc:	Linus Walleij <linus.walleij@...aro.org>,
	Vinod Koul <vinod.koul@...el.com>,
	linux-kernel@...r.kernel.org,
	Jassi Brar <jassisinghbrar@...il.com>,
	Magnus Damm <magnus.damm@...il.com>,
	Paul Mundt <lethal@...ux-sh.org>
Subject: Re: [PATCH/RFC] dmaengine: add a slave parameter to __dma_request_channel()

On Fri, 30 Mar 2012, Russell King - ARM Linux wrote:

> On Fri, Mar 16, 2012 at 03:28:39PM +0100, Guennadi Liakhovetski wrote:
> > Yessss!!! Let's do that! :-D Now, you're proposing exactly the same, as 
> > what I was proposing! :-) Now you just have to remove the filter function 
> > parameter from dma_request_channel() - it is anyway the same for all and 
> > implemented in the dmaengine core - and you get
> > 
> > dma_request_channel(mask, slave_desc)
> > 
> > which is exactly what I was proposing! :-)
> 
> Bollocks it is.  You're wanting to use the peripheral address, width
> and burst size to try to determine what channel to use.  That's a
> totally crackpot idea, and as I've already said several times it won't
> work in many real life cases we have already.

I'm afraid I'm just somehow failing to explain my thoughts to you, 
Russell. I don't think I ever said about using addresses, widths etc. They 
are not even used _now_ by the shdma.c driver. Why should I propose that 
then?

What I was proposing is to use some kind of an opaque slave ID for that. 
Which is, I think, pretty much the same as using a device pointer and DMA 
direction.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
--
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/