linux-kernel - Re: [RFCv2 3/3] ARM: dts: N900: Add SSI information

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] [day] [month] [year] [list]

Message-ID: <20131121233847.GB9772@earth.universe>
Date:	Fri, 22 Nov 2013 00:38:48 +0100
From:	Sebastian Reichel <sre@...g0.de>
To:	Tony Lindgren <tony@...mide.com>
Cc:	Linus Walleij <linus.walleij@...aro.org>,
	Shubhrajyoti Datta <omaplinuxkernel@...il.com>,
	Carlos Chinea <cch.devel@...il.com>,
	Paul Walmsley <paul@...an.com>,
	Kevin Hilman <khilman@...prootsystems.com>,
	Russell King <linux@....linux.org.uk>,
	Grant Likely <grant.likely@...aro.org>,
	Rob Herring <rob.herring@...xeda.com>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Stephen Warren <swarren@...dotorg.org>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Rob Landley <rob@...dley.net>,
	"'Benoît Cousson'" <bcousson@...libre.com>,
	devicetree@...r.kernel.org, linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-omap@...r.kernel.org
Subject: Re: [RFCv2 3/3] ARM: dts: N900: Add SSI information

On Thu, Nov 21, 2013 at 12:46:55PM -0800, Tony Lindgren wrote:
> * Sebastian Reichel <sre@...ian.org> [131120 18:22]:
> > On Wed, Nov 20, 2013 at 05:38:59PM -0800, Tony Lindgren wrote:
> > 
> > In the public documentation of the omaps all SSI related stuff is
> > missing and memory areas are marked as reserved. I could not find
> > out how to receive the NDA version, so the following is purely
> > speculation based on the code.
> > 
> > If I understand it right the HW looks like this:
> > 
> > +-----------------+
> > |    GDD (DMA)    | <- this one is currently called ssi-controller
> > +--------+--------+
> > | Port 1 | Port 2 | <- these are currently called ssi-port
> > +--------+--------+
> > 
> > I think the GDD part must be enabled while Port 1 or Port 2 is
> > enabled. The last RFC driver from Carlos did not even split up the
> > irq/memory areas into different platform devices, but just requested
> > all of them in one ssi platform device.
> 
> Might be worth checking. If these blocks have the revision and SYSC
> register in the beginning of their address space like all omap modules,
> then they are completely separate blocks and can idle independently.

This does not seem to be the case.
I think this is just one big IP-Core, which provides two ports.

> The fact that they have separate interrutps makes me think that's the
> case, otherwise there would be just interrupt(s) at the ssi-controllel
> level.

The original driver from Carlos had all IRQs in one big platform
device. I created the ports subdevices, since it looked cleaner
than naming resources "port1_mpu_irq0".

-- Sebastian

Download attachment "signature.asc" of type "application/pgp-signature" (837 bytes)