From Fedora Project Wiki
(update)
Line 16: Line 16:
* Percentage of completion: 80%
* Percentage of completion: 80%


Rawhide has the initial support for NVIDIA DisplayPort available in the nouveau kernel module.  There's a serious limitation in the current code: it's not able to configure displays that weren't previously configured by the video BIOS, the reasons for this are known but a solution isn't yet available.
Rawhide has the initial support for NVIDIA DisplayPort available in the nouveau kernel module.  There's a serious limitation in the current code: it's not able to configure displays that weren't previously configured by the video BIOS.  As a practical matter, this means the DisplayPort display must be connected at boot time to work.  The reasons for this are known but a solution isn't yet available.


To date it's known to have been tested on:
To date it's known to have been tested on:
Line 22: Line 22:
  NV96 + DP->VGA adaptor + Samsung 930B
  NV96 + DP->VGA adaptor + Samsung 930B
  MacBook Pro with GeForce 9400 + DP->VGA adaptor + Samsung 930B
  MacBook Pro with GeForce 9400 + DP->VGA adaptor + Samsung 930B
NV98 + HP LP2480zx


On the above configurations the displays operate as expected with the limitation mentioned above.
On the above configurations the displays operate as expected with the limitation mentioned above.
Line 33: Line 34:
== Benefit to Fedora ==
== Benefit to Fedora ==


DisplayPort has a higher link bandwidth than dual-link DVI.  Monitors can take advantage of this by providing higher resolutions, higher color depths, and higher refresh rates.  DisplayPort also runs at a lower voltage than DVI and LVDS, using less power.  Future laptops will likely switch to embedded DisplayPort for the local panel for this reason.  With this feature, Fedora users can take advantage of the the technical superiority of DisplayPort.
DisplayPort has a higher link bandwidth than dual-link DVI.  Monitors can take advantage of this by providing higher resolutions, higher color depths, and higher refresh rates.  DisplayPort also runs at a lower voltage than DVI and LVDS, using less power.  Future laptops will likely switch to embedded DisplayPort for the local panel for this reason.  With this feature, Fedora users can take advantage of the the technical superiority of DisplayPort on NVIDIA hardware.


== Scope ==
== Scope ==


Every device with a DisplayPort PHY will almost certainly need driver work to enable it.  At the moment this includes the big three of intel, radeon, and nouveau.  This feature only covers the nouveau driver.  See the [[Features/DisplayPort|Intel DisplayPort feature]] and the [[Features/RadeonDisplayPort|Radeon DisplayPort feature]] for the other two.  Some DisplayPort functionality will likely be common among all devices and can be lifted to helper routines in the X server or drm core.
Every device with a DisplayPort PHY will almost certainly need driver work to enable it.  This feature only covers the nouveau driver.  See the [[Features/DisplayPort|Intel DisplayPort feature]] and the [[Features/RadeonDisplayPort|Radeon DisplayPort feature]] for the other two.  Some DisplayPort functionality will likely be common among all devices and can be lifted to helper routines in the X server or drm core.


Affected packages:
Affected packages:
Line 57: Line 58:
== User Experience ==
== User Experience ==


DisplayPort connections should Just Work.
DisplayPort connections should Just Work.  They don't yet, but they're pretty close; X will work for non-hotplugged displays.


== Dependencies ==
== Dependencies ==


DisplayPort sinks with EDID are required to support EDID 1.4.  This is landed.
Updated nouveau kernel support, present in 2.6.32.
 
eDP sinks may use DisplayID instead.  X [http://cgit.freedesktop.org/xorg/xserver/commit/?id=0bb9a7e1650180a24246d14493a8168487cf8914 implements] a DisplayID decode but no fetch mechanism.  But we don't have any eDP devices to test with yet, so who knows.
 
Possible common functionality: link/lane computation, manual link training, dongle identification, various other AUXCH services.
 
Some IHV communication may be necessary to get details on specific DP PHYs.


== Contingency Plan ==
== Contingency Plan ==
Line 75: Line 70:
== Documentation ==
== Documentation ==


Ideally, none needed, besides "DisplayPort just works now".  It's not like we have documentation for DVI.
DisplayPort devices must be plugged in at system boot time to work.


== Release Notes ==
== Release Notes ==


DisplayPort is likely to require kernel support in a much stronger way than DVI, since hotplugging the monitor requires another link training cycle, and the only reliable way to detect that is with interrupts.  UMS configurations may accidentally work in some situations, but this is not recommended.
None.


== Comments and Discussion ==
== Comments and Discussion ==

Revision as of 22:59, 25 February 2010

DisplayPort support for Nouveau

Summary

Enhanced support for DisplayPort in X and kernel drivers for NVIDIA hardware.

Owner

  • Name: Ben Skeggs
  • email: bskeggs@redhat.com

Current status

  • Targeted release: Fedora 13
  • Last updated: 2010-02-23
  • Percentage of completion: 80%

Rawhide has the initial support for NVIDIA DisplayPort available in the nouveau kernel module. There's a serious limitation in the current code: it's not able to configure displays that weren't previously configured by the video BIOS. As a practical matter, this means the DisplayPort display must be connected at boot time to work. The reasons for this are known but a solution isn't yet available.

To date it's known to have been tested on:

NV96 + Dell 2408WFP
NV96 + DP->VGA adaptor + Samsung 930B
MacBook Pro with GeForce 9400 + DP->VGA adaptor + Samsung 930B
NV98 + HP LP2480zx

On the above configurations the displays operate as expected with the limitation mentioned above.

DisplayPort -> DVI connections should work as well as native DVI, and are not subject to the limitation mentioned above.

Detailed Description

DisplayPort is a new digital display connector and protocol. While much more capable than DVI, it's also much more complicated, and some work is needed to take advantage of it.

Benefit to Fedora

DisplayPort has a higher link bandwidth than dual-link DVI. Monitors can take advantage of this by providing higher resolutions, higher color depths, and higher refresh rates. DisplayPort also runs at a lower voltage than DVI and LVDS, using less power. Future laptops will likely switch to embedded DisplayPort for the local panel for this reason. With this feature, Fedora users can take advantage of the the technical superiority of DisplayPort on NVIDIA hardware.

Scope

Every device with a DisplayPort PHY will almost certainly need driver work to enable it. This feature only covers the nouveau driver. See the Intel DisplayPort feature and the Radeon DisplayPort feature for the other two. Some DisplayPort functionality will likely be common among all devices and can be lifted to helper routines in the X server or drm core.

Affected packages:

  • kernel
  • xorg-x11-server
  • xorg-x11-drv-nouveau

How To Test

Test hardware with display port sources by connecting to a DisplayPort sink, DP-to-HDMI converter, DP-to-DVI converter, and DP-to-VGA converter. For each of these cases, also test hotplug switching. When laptops start showing up with embedded DisplayPort support, test the internal laptop screen.

Known DP sinks:

  • Apple: 24" LED
  • Dell: 2408WFP, 3008WFP
  • HP: LP2275w, LP2480zx

User Experience

DisplayPort connections should Just Work. They don't yet, but they're pretty close; X will work for non-hotplugged displays.

Dependencies

Updated nouveau kernel support, present in 2.6.32.

Contingency Plan

None necessary. It doesn't work in previous Fedora releases, so it can continue to not work in F13.

Documentation

DisplayPort devices must be plugged in at system boot time to work.

Release Notes

None.

Comments and Discussion