linux-kernel - Re: [PATCH] clk: sunxi-ng: ccu-sun4i-a10: Fix mali changing dclk frequency

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: <20180201124551.kfyz6frx4lcx4wbz@flea.lan>
Date:   Thu, 1 Feb 2018 13:45:51 +0100
From:   Maxime Ripard <maxime.ripard@...e-electrons.com>
To:     Giulio Benetti <giulio.benetti@...ronovasrl.com>
Cc:     Chen-Yu Tsai <wens@...e.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...eaurora.org>,
        linux-arm-kernel@...ts.infradead.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] clk: sunxi-ng: ccu-sun4i-a10: Fix mali changing dclk
 frequency

On Wed, Jan 31, 2018 at 01:05:38PM +0100, Giulio Benetti wrote:
> Hi,
> 
> Il 31/01/2018 09:43, Maxime Ripard ha scritto:
> > Hi,
> > 
> > On Wed, Jan 31, 2018 at 12:23:59AM +0100, Giulio Benetti wrote:
> > > When mali.ko is inserted, it set default clocks and call all parent
> > > clocks to stay into range, causing pll-video0 to change and
> > > subsequently to change dclk to wrong frequencies.
> > 
> > This is what you should fix.
> 
> Ok, so it must be patch title(shrinked of course), right?
> 
> > 
> > > "gpu" clock has lot of parent plls inside driver, but on sun7i
> > > pll8-gpu does not depend on pll-video0, pll-ve, pll-video1.
> > > 
> > > It only depends on 24Mhz main clock.
> > 
> > I don't really know why you are mentionning that. The GPU clock has
> > all the parents described in the driver. And the parents' parents are
> > irrelevant to this particular issue.
> > 
> > > Remove all pll parents from gpu_parents_sun7i except "pll-gpu".
> > 
> > However, this is not a proper fix for your issue.
> 
> Yes, you're right, now I understand.
> 
> It is more complex than I thought.
> I need to dig more and study better A20 CCU.
> 
> So this patch can be dropped.
> 
> > 
> > What kernel version did you use?
> 
> Latest mainline.

I guess this patch could fix it:
http://code.bulix.org/1kitrq-268936?raw

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)