[Bug 111516] New: make 'respect_downstream_limits' configurable

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=111516

            Bug ID: 111516
           Summary: make 'respect_downstream_limits' configurable
           Product: DRI
           Version: unspecified
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: not set
         Component: DRM/Intel
          Assignee: intel-gfx-bugs at lists.freedesktop.org
          Reporter: munderl at tnt.uni-hannover.de
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
                CC: intel-gfx-bugs at lists.freedesktop.org

Created attachment 145203
  --> https://bugs.freedesktop.org/attachment.cgi?id=145203&action=edit
The boolean should be configurable as a module option

In our  company, we have a lot of Dell U2713HM in use. We recently switch from
nvida to onboard intel graphics for all our computers and now have the problem
that these old monitors only support their full resolution (2560x1440) on
Dual-Link DVI or DP. On our mainboards, only the HDMI output is available. On
HDMI, the monitor only supports 1920x1080.

However, if the port_clock is increased beyond limits, the 2560x1440 mode works
perfectly fine with this monitor. I used the monitor for years this way, until
it suddenly did not work anymore because the respect_port_limits was included
to intel_hdmi.c as a bug fix - which broke it for me.

I understand that the problem is the monitor firwmare, but I am patching my
kernel for years now whithout problems (I'm uisng the intel graphics since we
bought the monitors) and I always hoped that the fixed boolean will once become
a configurable module parameter - which never happend.

So I'm asking if it would be possible to make the fixed boolean a module
parameter (like respect_port_clock_limit or so). I'm not good at kernel
programming so I don't really know how to do this, but I provided a patch where
the boolean needs to be placed.

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are the QA Contact for the bug.
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20190829/47e3fe36/attachment.html>