Bug#421095: Detects a non-existing monitor on the non-existing secondary head

[Alex Deucher]

On 8/14/07, Gabor Gombas <gombasg at sztaki.hu> wrote:
> On Sat, Aug 11, 2007 at 06:28:56PM +0200, Brice Goglin wrote:
>
> > If the bug is still there with 6.6.193-1 (in experimental), I'll forward
> > on the upstream bugzilla so that it gets attention before driver 6.7 is
> > released.
>
> 6.6.3:

> (II) RADEON(0): Primary:
>  Monitor   -- CRT
>  Connector -- VGA
>  DAC Type  -- Primary
>  TMDS Type -- NONE
>  DDC Type  -- VGA_DDC
> (II) RADEON(0): Secondary:
>  Monitor   -- NONE
>  Connector -- None
>  DAC Type  -- Unknown
>  TMDS Type -- NONE
>  DDC Type  -- NONE
>
> 6.6.193:

> (II) RADEON(0): Port1:
>  Monitor   -- CRT
>  Connector -- VGA
>  DAC Type  -- Primary
>  TMDS Type -- External
>  DDC Type  -- VGA_DDC
> (II) RADEON(0): Port2:
>  Monitor   -- CRT
>  Connector -- VGA
>  DAC Type  -- Primary
>  TMDS Type -- External
>  DDC Type  -- VGA_DDC
> (II) RADEON(0): ---- Primary Head:   Port1 ----
> (II) RADEON(0): ---- Secondary Head: Port2 ----
>
>
> So it still thinks that the card has two heads and it detects my monitor
> on the non-existing head too.
>

There's an issue with master applying the same DDC channel to both
ports on some cards.  I'm looking into it.  It looks like the same
connector is in the bios table twice.  Because the driver thinks both
channels are using the same port, they are both seeing the same
monitor.  See bug 11781:
https://bugs.freedesktop.org/show_bug.cgi?id=11781
As a work around for now you can specify a monitorlayout to disable
the secondary head:
Option "MonitorLayout" "CRT, NONE"

Alex