[Bug 25992] New: ATI Radeon 7000 video card cannot display some DVI modes

[bugzilla-daemon at freedesktop.org]

http://bugs.freedesktop.org/show_bug.cgi?id=25992

           Summary: ATI Radeon 7000 video card cannot display some DVI modes
           Product: xorg
           Version: 7.1
          Platform: All
        OS/Version: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Driver/Radeon
        AssignedTo: xorg-driver-ati at lists.x.org
        ReportedBy: rmacdona at ati.com
         QAContact: xorg-team at lists.x.org
                CC: cooper.yuan at amd.com


Description of problem:

ATI Radeon 7000 video cards will not reliably display high video modes such as
1600x1200 or 1920x1200 using DVI.   The same modes though VGA work fine.  There
is a temperature dependence in the ASIC used on the video card (part number
215R6LAEA12G).  Cards with other ASICs such as 215R6LAFA12E do not seem to be
affected.  

Since DVI panels have become cheap and plentiful recently we can expect to see
this problem more often as older systems are connected to new DVI monitors.   


Affected component:

ATI Radeon 7000 video cards with AMD Part number: 102-85537-00 
Or HP Part number:  AH391A 


Steps to Reproduce:
1. Use the DVI output of the Radeon 7000

2. Use a monitor capable of displaying at least 1600x1200 at 60 Hz with a pixel
clock of 162MHz.  Determine the clock using "xrandr --verbose".  Or if your
version of xrandr doesn't provide this find the modeline in /var/log/Xorg.0.log
and read the clock value there, OR use an oscilloscope to view DVI connector
pins 23 and 24 (TMDS differential clock).

3. Apply heat to the video chip.   

Actual results:

Failure (black screen) will often occur between 30C to 50C. 


Expected results:
Normal video up to at least 50C.

Additional info:

The original design limit for the DVI output of the Radeon 7000 was 108MHz. 
Testing has shown 135MHz to be stable.  

To handle this problem, the video driver should restrict modes to at least
135MHz for these cards.  

Sixteen cards were tested at AMD after being returned from HP customers.  All
cards failed at DVI/162MHz.  None of the cards failed at DVI/135MHz.


-- 
Configure bugmail: http://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.