displayport detects monitoring, but monitor goes into power saving

Dave Airlie airlied at gmail.com
Tue Aug 5 16:37:16 PDT 2014

On 5 August 2014 18:56, Glen Ogilvie <nelg at linuxsolutions.co.nz> wrote:
> Hi,
> I've got a problem, that I'd like a little help with getting to the bottom
> of... so looking for a little advise.
> I can't get my laptop's displayport output to drive my monitor, using the
> free ati driver.  It does work on the legacy driver, from ATI, however, that
> only works on X <= 1.12, which is no fun to be stuck with, as no current
> distro ships old versions of X.  I have a 27 inch dell monitor, so using
> HDMI is not great option, as it can't drive a high enough resolution to look
> sharp, as I want 2560 x 1440.
> I think Bug 45291 is basically the same problem, and I've updated it to
> include my hardware as well.
> I am looking for some advise, as to what I can do to help the smart graphics
> driver developers here get to the bottom of this.. as it's becoming a pain
> for me to live with a 4 year old Distro, or have to replace my laptop, which
> is otherwise working great for me.
> I've tried kernel 3.15.6, which is a great improvement, as the power
> management seems to work, so the GPU fan's don't run full speed the whole
> time, but still have the issues with displayport.
> So, I assume to help, I could provide xorg logs, dmesg, lspci, dmidecode..
> but what else.. in all of these, no where can I see any errors, as the
> monitor is detected.. just no output.   Trying the same monitor with hdmi,
> works, but the resolution is limited, as HDMI can't drive resolutions above
> 1920x1200 as far as I know.

file a bug on bugs.freedesktop.org, and attach a boot with drm.debug=6 to start

it might be possible to work it out from there.

Also the monitor model etc would be good.


More information about the xorg-driver-ati mailing list