kernel-packages team mailing list archive

[StoatWblr <1303150@xxxxxxxxxxxxxxxxxx>]

Public bug reported:

As the summary says. This is 100% repeatable and there's been a fair
amount of traffic about it on various lists.

The current concensus is that the root cause is down to to powersave
mode tweaks in all GPU modules

To repeat:

install multiple nvidia GPUs in a desktop system (or a multi-gpu card
such as nvidia Quadro CVS440)

Boot up Trusty beta versions (or 2.13 kernel).

try configuring displays using standard tools based on xrandr

This worked fine in Saucy (crosscheck: boot off 13.10 64bit DVD)

Apparently this is fixed in the 2.14 kernels.

It can be worked around by manually configuring the devices in xorg.conf
and enabling Xinerama, BUT - this results in massive slowdown and as
this disables xrandr a number of important apps (such as vlc) will
refuse to run.

This is a major regression and needs to be treated as such.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: gpu

** Description changed:

  As the summary says. This is 100% repeatable and there's been a fair
  amount of traffic about it on various lists.
  
  The current concensus is that the root cause is down to to powersave
  mode tweaks in all GPU modules
  
  To repeat:
  
  install multiple nvidia GPUs in a desktop system (or a multi-gpu card
  such as nvidia Quadro CVS440)
  
  Boot up Trusty beta versions (or 2.13 kernel).
  
  try configuring displays using standard tools based on xrandr
  
  This worked fine in Saucy (crosscheck: boot off 13.10 64bit DVD)
  
  Apparently this is fixed in the 2.14 kernels.
  
  It can be worked around by manually configuring the devices in xorg.conf
  and enabling Xinerama, BUT - this results in massive slowdown and as
  this disables xrandr a number of important apps (such as vlc) will
  refuse to run.
+ 
+ This is a major regression and needs to be treated as such.

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1303150

Title:
  2.13 kernels (ALL) : Multihead multi-gpu broken for at least Nvidia
  GPUs

Status in “linux” package in Ubuntu:
  New

Bug description:
  As the summary says. This is 100% repeatable and there's been a fair
  amount of traffic about it on various lists.

  The current concensus is that the root cause is down to to powersave
  mode tweaks in all GPU modules

  To repeat:

  install multiple nvidia GPUs in a desktop system (or a multi-gpu card
  such as nvidia Quadro CVS440)

  Boot up Trusty beta versions (or 2.13 kernel).

  try configuring displays using standard tools based on xrandr

  This worked fine in Saucy (crosscheck: boot off 13.10 64bit DVD)

  Apparently this is fixed in the 2.14 kernels.

  It can be worked around by manually configuring the devices in
  xorg.conf and enabling Xinerama, BUT - this results in massive
  slowdown and as this disables xrandr a number of important apps (such
  as vlc) will refuse to run.

  This is a major regression and needs to be treated as such.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1303150/+subscriptions