linux-kernel - Re: [PATCH v2 2/2] drm: fsl-dcu: enable PIXCLK on LS1021A

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: <mbgd2mjqjhlytvpkljrvlcva7qzahex4qcrfusy2vijz6ysq7a@6baliilco6ab>
Date: Sat, 19 Oct 2024 17:30:57 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Alexander Stein <alexander.stein@...tq-group.com>
Cc: Stefan Agner <stefan@...er.ch>, Alison Wang <alison.wang@....com>, 
	David Airlie <airlied@...il.com>, Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
	Maxime Ripard <mripard@...nel.org>, Simona Vetter <simona@...ll.ch>, Daniel Vetter <daniel@...ll.ch>, 
	Matthias Schiffer <matthias.schiffer@...group.com>, Thomas Zimmermann <tzimmermann@...e.de>, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] drm: fsl-dcu: enable PIXCLK on LS1021A

On Thu, Oct 17, 2024 at 08:50:43AM +0200, Alexander Stein wrote:
> Hi everyone,
> 
> Am Freitag, 27. September 2024, 01:13:57 CEST schrieb Dmitry Baryshkov:
> > On Thu, Sep 26, 2024 at 04:09:03PM GMT, Alexander Stein wrote:
> > > Hi Dmitry,
> > > 
> > > Am Donnerstag, 26. September 2024, 08:05:56 CEST schrieb Dmitry Baryshkov:
> > > > On Thu, Sep 26, 2024 at 07:55:51AM GMT, Alexander Stein wrote:
> > > > > From: Matthias Schiffer <matthias.schiffer@...group.com>
> > > > > 
> > > > > The PIXCLK needs to be enabled in SCFG before accessing certain DCU
> > > > > registers, or the access will hang. For simplicity, the PIXCLK is enabled
> > > > > unconditionally, resulting in increased power consumption.
> > > > 
> > > > By this description it looks like a fix. What is the first broken
> > > > commit? It needs to be mentioned in the Fixes: tag. Or is it hat
> > > > existing devices have been enabling SCFG in some other way?
> > > 
> > > We discussed this internally and it seems this never worked, unless PIXCLK
> > > was already enabled in SCFG by a different way, e.g. firmware, etc.
> > 
> > My bet was on the firmware, but I never touched Layerscape platforms.
> > Anyway,
> > 
> > Fixes: 109eee2f2a18 ("drm/layerscape: Add Freescale DCU DRM driver")
> > Acked-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> 
> Any additional feedback?

No response from Stefan and Alison for nearly a month...

-- 
With best wishes
Dmitry