linux-kernel - Re: [Intel-gfx] [PATCH 06/21] drm/i915: Unlock PCH_PP

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: <yunty7t62sf.fsf@aiko.keithp.com>
Date:	Fri, 30 Sep 2011 16:14:40 -0700
From:	Keith Packard <keithp@...thp.com>
To:	Daniel Vetter <daniel@...ll.ch>
Cc:	Dave Airlie <airlied@...hat.com>, intel-gfx@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH 06/21] drm/i915: Unlock PCH_PP_CONTROL always

On Fri, 30 Sep 2011 19:09:46 +0200, Daniel Vetter <daniel@...ll.ch> wrote:

> grep shows that we also write to PCH_PP_CONTROL in intel_lvds.c in the
> dpms functions - any reasons these two writes are left out?

Upon a bit of review:

  The bspec makes it clear that this write protect key only needs to
  be written for eDP on DPA -- it's a work-around for a bug where panel
  power sequencing wouldn't work right.

  The LVDS code does disable write protect in the _init function, which
  seems global enough, but misses the resume case. We shouldn't ever
  need to set this field though; it write protects registers only
  when the panel is running. We could presumably remove the
  write protect disable entirely in the LVDS code.

So, I think the patch as written is correct.

-- 
keith.packard@...el.com

Content of type "application/pgp-signature" skipped