Ubuntu
linux package

  1. Bug #891270
  2. Comment #5

Comment 5 for bug 891270

Revision history for this message
Manoj Iyer (manjo) wrote :

SRU JUSTIFICATION
================

ISSUE
=====
Ivybridge system fails to resume from S3/S4 with recent BIOS. On system resume causes kernel oops in i915 driver.

FIX
===
Upstream fixed the issue by adding multi-threaded forcewake support.
On IVB C0+ with newer BIOSes, the forcewake handshake has changed. There's
now a bitfield for different driver components to keep the GT powered
on. On Linux, we centralize forcewake handling in one place, so we
still just need a single bit, but we need to use the new registers if MT
forcewake is enabled.

TEST
=====
This patch was tested on Ivybridge system with the kernel posted at http://kernel.ubuntu.com/~sarvatt/fdo42923/ and the test results are noted in comment #3 in this bug, and also reported the same to https://bugs.freedesktop.org/show_bug.cgi?id=42923