[Bug 94959] New: Booting Intel HD Graphics 5500 without intel_iommu=igfx_off is unworkable.

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=94959

            Bug ID: 94959
           Summary: Booting Intel HD Graphics 5500 without
                    intel_iommu=igfx_off is unworkable.
           Product: xorg
           Version: 7.4 (2008.09)
          Hardware: x86-64 (AMD64)
                OS: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Driver/intel
          Assignee: chris at chris-wilson.co.uk
          Reporter: ad_sicks at yahoo.com
        QA Contact: intel-gfx-bugs at lists.freedesktop.org

Created attachment 122982
  --> https://bugs.freedesktop.org/attachment.cgi?id=122982&action=edit
gpu dump.

According to the document Documentation/Intel-IOMMU.txt a bug report is needed
if the intel_iommu=igfx_off kernel parameter fixes and issues. Well, it did on
my machine.  Specs:

 lspci
00:00.0 Host bridge: Intel Corporation Broadwell-U Host Bridge -OPI (rev 09)
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated
Graphics (rev 09)

...

00:1c.0 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #1
(rev e3)
00:1c.2 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #3
(rev e3)
00:1c.3 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #4
(rev e3)

...

00:1f.0 ISA bridge: Intel Corporation Wildcat Point-LP LPC Controller (rev 03)
00:1f.3 SMBus: Intel Corporation Wildcat Point-LP SMBus Controller (rev 03)
00:1f.6 Signal processing controller: Intel Corporation Wildcat Point-LP
Thermal Management Controller (rev 03)

Graphics stack:
X.Org X Server 1.18.3
Release Date: 2016-04-04
X Protocol Version 11, Revision 0
Build Operating System: Linux 4.2.0-35-lowlatency x86_64 Gentoo
Current Operating System: Linux gentoo-laptop 4.4.6-gentoo #1 SMP Fri Apr 15
18:09:05 CDT 2016 x86_64
Kernel command line: BOOT_IMAGE=/kernel-genkernel-x86_64-4.4.6-gentoo
intel_iommu=igfx_off i915.preliminary_hw_support=0 dolvm
real_root=/dev/ubuntu-studio-vg/lv_gentoo_root init=/usr/lib/systemd/systemd ro
rootfsype=ext4
Build Date: 15 April 2016  07:16:47PM

Current version of pixman: 0.32.8
    Before reporting problems, check http://wiki.x.org
    to make sure that you have the latest version.

** (Happens on older versions also)

Kernel:
linux-4.4.6 x86_64 Intel(R) Core(TM) i3-5010U CPU @ 2.10GHz GenuineIntel 

** (Happened on 4.1.15 also)
Problems:
With IOMMU turned on:
1. bad modesetting (wrong modes, maybe confused contexts also)
2. random 'stuck on render ring' errors 
3. freezes (sometimes at the DM level, other times after the WM has started and
an app is attempted to be opened)
4. outright crashes occur. (sometimes as early as Plymouth, sometimes at DM
level, Sometimes as a WM starts)

Happens with only the laptop display or with an external monitor hooked to DP1.

I will attach a gpu core dump I managed to capture from one when either
starting X or maybe even at Plymouth (yeah, plymouth doesn't even work reliably
without this parameter). However, i think the actually dump was from an older
version setup, but the results were the same with this version.....

I would also be happy to reboot with IOMMU turned on and do whatever and pull
which ever logs will help.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20160416/238f18a9/attachment-0001.html>