[Intel-gfx] [RFC] Three pipe support for IVB

[Jesse Barnes]

On Wed,  5 Oct 2011 10:25:17 -0700
Jesse Barnes <jbarnes at virtuousgeek.org> wrote:

> This set of patches lays the groundwork for supporting 3 pipes on IVB
> hardware.  We've only tested it so far with 2 HDMI plus 1 VGA (a
> configuration that doesn't work), and are awaiting 3 DP port hardware
> (the officially supported config) to complete our testing.
> 
> So this patchset is necessary but may not be sufficient (once we have 3
> DP hardware we can debug and see).  Review and comments appreciated.

Gordon, I think this set (with the updated 4/4 patch) is ready for
testing.  You'll need a configuration that uses the same monitor on two
identical ports to get all the pipes running.  I'm also interested in
the failure cases though.  There are some limitations:
  1) two heads need to use the same timings and ports
  2) FDI B and C share lanes, so are limited to a max of two lanes each

For (1), I'm currently using a VGA attached monitor, an HDMI attached
monitor, and another HDMI monitor attached to a DP->HDMI dongle on my
SDV (that allows me to drive the port with the HDMI encoder rather than
the DP encoder).

Unfortunately, (2) complicates our mode list output.  If you query for
available modes, you'll definitely see some that you can't drive with 3
pipes enabled.  I'm not sure if the best way to handle that...

-- 
Jesse Barnes, Intel Open Source Technology Center
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/intel-gfx/attachments/20111005/fa135a15/attachment.sig>