linux-kernel - Re: [PATCH] drm/sysfs: Provide per connector control of DRM KMS polling

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: <20100922114419.7f9766c5@schatten.dmk.lab>
Date:	Wed, 22 Sep 2010 11:44:19 +0200
From:	Florian Mickler <florian@...kler.org>
To:	Andy Walls <awalls@...metrocast.net>
Cc:	Greg KH <greg@...ah.com>, linux-kernel@...r.kernel.org,
	dri-devel@...ts.freedesktop.org, Dave Airlie <airlied@...hat.com>,
	Jon Smirl <jonsmirl@...il.com>,
	Rafał Miłecki <zajec5@...il.com>,
	Alex Deucher <alexdeucher@...il.com>,
	Chris Wilson <chris@...is-wilson.co.uk>
Subject: Re: [PATCH] drm/sysfs: Provide per connector control of DRM KMS
 polling

[cc'd chris wilson]

Hi Andy!

On Mon, 20 Sep 2010 19:02:30 -0400
Andy Walls <awalls@...metrocast.net> wrote:

> BTW, I found that Chris Wilson recently committed a change to inhibit
> all drm connector polling globally for a different reason:
> 
> http://git.kernel.org/?p=linux/kernel/git/airlied/drm-2.6.git;a=commit;h=e58f637bb96d5a0ae0919b9998b891d1ba7e47c9
> 
> That commit message shows a case where the driver decides polling needs
> to happen, but the human knows differently and manual control over
> connector polling mitigates the problem.


On Mon, 20 Sep 2010 17:11:48 -0400
Andy Walls <awalls@...metrocast.net> wrote:

> On Mon, 2010-09-20 at 11:52 -0700, Greg KH wrote:
> > On Mon, Sep 20, 2010 at 08:59:00AM -0400, Andy Walls wrote:
>  
> > > This change allows the root user to disable (and re-enable) DRM KMS
> > > connector polling on a per connector basis via sysfs, like so:
> > > 
> > >         # cat /sys/class/drm/card0/card0-DVI-D-1/polled
> > >         [hotplug_detectable] connect disconnect
> 
> > You are adding a sysfs file, yet you forgot to add a file in
> > Documentation/ABI.  Please fix that and resend the patch.
> 
> Oops, process failure, sorry.
> Will do.
> 
> Regards,
> Andy
> 

I thought sysfs files should be one thing per file... so, maybe
card0-DVI-D-1/link_status and card0-DVI-D-1/hotplug_detectable with 0/1
content would be easier to manipulate and parse? 

I have to defer to the drm maintainers for the usecases. But how is
having a monitor with a broken edid handled right now? While the output
is connected and used, it probably just stops polling?

cheers,
Flo




--
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/