linux-kernel - Re: [PATCH v2] drm/i915: Fix lock dropping in intel_tv

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: <20140902082635.GA25238@nuc-i3427.alporthouse.com>
Date:	Tue, 2 Sep 2014 09:26:35 +0100
From:	Chris Wilson <chris@...is-wilson.co.uk>
To:	Ville Syrjälä <ville.syrjala@...ux.intel.com>
Cc:	Jani Nikula <jani.nikula@...ux.intel.com>,
	intel-gfx@...ts.freedesktop.org, David Airlie <airlied@...ux.ie>,
	Daniel Vetter <daniel.vetter@...ll.ch>,
	linux-kernel@...r.kernel.org, Tibor Billes <tbilles@....com>
Subject: Re: [PATCH v2] drm/i915: Fix lock dropping in intel_tv_detect()

On Tue, Sep 02, 2014 at 11:16:12AM +0300, Ville Syrjälä wrote:
> On Tue, Sep 02, 2014 at 10:41:05AM +0300, Jani Nikula wrote:
> > On Mon, 01 Sep 2014, Chris Wilson <chris@...is-wilson.co.uk> wrote:
> > > On Mon, Sep 01, 2014 at 01:36:37PM +0300, Ville Syrjälä wrote:
> > >> On Mon, Sep 01, 2014 at 11:20:09AM +0100, Chris Wilson wrote:
> > >> > On Mon, Sep 01, 2014 at 01:07:40PM +0300, ville.syrjala@...ux.intel.com wrote:
> > >> > > From: Ville Syrjälä <ville.syrjala@...ux.intel.com>
> > >> > > 
> > >> > > When intel_tv_detect() fails to do load detection it would forget to
> > >> > > drop the locks and clean up the acquire context. Fix it up.
> > >> > > 
> > >> > > This is a regression from:
> > >> > >  commit 208bf9fdcd3575aa4a5d48b3e0295f7cdaf6fc44
> > >> > >  Author: Ville Syrjälä <ville.syrjala@...ux.intel.com>
> > >> > >  Date:   Mon Aug 11 13:15:35 2014 +0300
> > >> > > 
> > >> > >     drm/i915: Fix locking for intel_enable_pipe_a()
> > >> > > 
> > >> > > v2: Make the code more readable (Chris)
> > >> > > 
> > >> > > Cc: Tibor Billes <tbilles@....com>
> > >> > > Signed-off-by: Ville Syrjälä <ville.syrjala@...ux.intel.com>
> > >> > 
> > >> > Hmm, if we use WARN_ON() you should init type.
> > >> 
> > >> type is always set in the branch that sets status=connected.
> > >
> > > Back to thinking about readability and making sure that the WARN_ON
> > > never happens with just a glance. Otherwise, the WARN_ON would be better
> > > as WARN_ON(unsigned)type >= last_tv_type); Or something. Anway, take
> > > your pick and slap my r-b on it. :)
> > 
> > Ville?
> 
> I don't know anymore. Just kill the WARN_ON() if it makes things
> confusing?

Just drop the WARN_ON. I prefer the if() using the status rather than
type, as that seems more idiomatic (when looking at our other detection
routines).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre
--
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/