Bug 748375

$ xrandr
Screen 0: minimum 640 x 400, current 1280 x 1024, maximum 1280 x 1024
default connected 1280x1024+0+0 0mm x 0mm
   1280x1024      60.0*    75.0  
   1280x960       60.0  
   1280x800       75.0     60.0  
   1152x864       75.0  
   1280x768       75.0     60.0  
   1024x768       75.0     60.0     70.0  
   800x600        75.0     60.0     72.0     56.0  
   848x480        60.0  
   640x480        75.0     60.0     73.0  
   720x400        70.0

Also not able to rotate screen. But here Im not sure if MGA even support rotating.

mga multihead is known to be quite limited, yes.

Moving to 6.3.

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

This request was erroneously removed from consideration in Red Hat Enterprise Linux 6.4, which is currently under development.  This request will be evaluated for inclusion in Red Hat Enterprise Linux 6.4.

The Dual-Head support in the mainstream development (freedesktop.org) of the MGA driver was broken in August 2007, when they introduced the so called "Pci Rework", a code rework to use the new PCI Access library. If compiled to use that new library, the driver could no more map the second head's frame buffer. Fortunately, RHEL didn't experience the problem for long time because its Xorg Server didn't use the Pci Access library. The problem has come out since RHEL 6.2 with the introduction of a new Xorg Server compiled for Pci Access use.

So several years have passed and it seems that there's no interest in the mainstream development to fix the broken Dual-Head feature. That's really surprising because:

- the feature is of mainly importance for Millennium cards;
- fixing the issue is quite simple;
- the experimental RandR support, which should have solved the problem and much more, is abandoned for years now and has become totally out of sync with current Xorg servers (probably it was too buggy).

As already said, fixing the Dual-Head "Pci Rework" issue is quite simple. A well known fix for ver. 1.4.11 of the MGA driver by Andy Mac Lean has long been available on the internet and used by many people. I re-wrote the fix for ver. 1.4.13 (the one in RHEL 6.2) doing a bit of code cleaning and adding some minor changes: you'll find it attached to this bug. 

With that fix I patched the RHEL 6.2 SRPM (xorg-x11-drv-mga-1.4.13-3.el6.src.rpm) and updated the official installed binary package. I'm using that custom package for several months without any trouble on a Matrox G550 PCIe in Dual-Head configuration.

Created attachment 602167 [details]
Patch resolving the issue (see Comment 9)

Fix for the Dual-Head "Pci Rework" issue as illustrated inside Comment 9.

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

Red Hat Enterprise Linux 6 is in the Production 3 Phase. During the Production 3 Phase, Critical impact Security Advisories (RHSAs) and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available.

The official life cycle policy can be reviewed here:

http://redhat.com/rhel/lifecycle

This issue does not meet the inclusion criteria for the Production 3 Phase and will be marked as CLOSED/WONTFIX. If this remains a critical requirement, please contact Red Hat Customer Support to request a re-evaluation of the issue, citing a clear business justification. Note that a strong business justification will be required for re-evaluation. Red Hat Customer Support can be contacted via the Red Hat Customer Portal at the following URL:

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