linux-kernel - Re: [drm:drm_calc_timestamping_constants [drm]] *ERROR* crtc 21: Can't calculate constants, dotclock = 0!

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: <20151001111309.GA26517@intel.com>
Date:	Thu, 1 Oct 2015 14:13:09 +0300
From:	Ville Syrjälä <ville.syrjala@...ux.intel.com>
To:	Jiri Kosina <jikos@...nel.org>
Cc:	maarten.lankhorst@...ux.intel.com, linux-kernel@...r.kernel.org,
	intel-gfx@...ts.freedesktop.org,
	Jani Nikula <jani.nikula@...ux.intel.com>
Subject: Re: [drm:drm_calc_timestamping_constants [drm]] *ERROR* crtc 21:
 Can't calculate constants, dotclock = 0!

On Thu, Oct 01, 2015 at 11:41:34AM +0200, Jiri Kosina wrote:
> Hi,
> 
> since I've updated on my thinkpad x200s to latest Linus' tree (3235031), I 
> am getting a lot of
> 
> 	[drm:drm_calc_timestamping_constants [drm]] *ERROR* crtc 21: Can't calculate constants, dotclock = 0!

What's a lot? I think you should see at most a few during driver load,
and maybe resume.

If you're seeing more during runtime, then I think there must be a more
serious bug somewhere.

> 
> googling revealed this patch:
> 
> 	http://permalink.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/67471
> 
> is there any reason why it's not present upstream?

There's a v2 of that patch in some tree. Hmm. Seems to be in
drm-intel-next-queued. Maybe it should get bumped to -fixes?

There's also another one that kills some of those message on certain
platforms:
0f64614dde17 drm/i915: Fix clock readout when pipes are enabled w/o ports

-- 
Ville Syrjälä
Intel OTC
--
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/