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Bug 1082815 - ARM Kernels 3.13+ have no working display when using a DTB
Summary: ARM Kernels 3.13+ have no working display when using a DTB
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: rawhide
Hardware: arm
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Kyle McMartin
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks: ARMTracker
TreeView+ depends on / blocked
 
Reported: 2014-03-31 21:12 UTC by Paul Whalen
Modified: 2015-09-01 03:54 UTC (History)
14 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2014-09-23 17:42:35 UTC
Type: Bug
Embargoed:

Attachments (Terms of Use)

Description Paul Whalen 2014-03-31 21:12:33 UTC 
Description of problem:
When booting with a DTB using kernels 3.13+ all platforms lack a working display. Booting without a DTB in vexpress continues to work. 

This seems to affect all boards tested - specifically the Trimslice and Pandaboard which were working prior.
Comment 1 Kai Reichert 2014-04-21 20:13:17 UTC 
I can confirm this on a pandaboard. In the meantime it can boot with a DTB for current kernels on fedora 20, but the HDMI display is not working.

In prior kernel versions without DTB I a get display at full 1920x1080 pixel resolution.
Comment 2 Paul Whalen 2014-05-27 14:31:17 UTC 
Display is working again on the Pandaboard in kernel-3.15.0-0.rc5.git2.10.fc21+ using rawhide nightlies.
Comment 3 Adam Williamson 2014-07-30 17:54:28 UTC 
F20 is now on a 3.15 kernel in stable updates. Does this mean this is fixed for F20/F21/F22 now? F19 is still on 3.14.
Comment 4 Josh Boyer 2014-07-30 18:01:49 UTC 
FYI, F19 is staying on 3.14.y until EOL.  If 3.15 is required for this bug then users will need to migrate to F20.
Comment 5 info@kobaltwit.be 2014-09-05 10:03:31 UTC 
I recently installed Fedora 20 on my trimslice. This installer image works well, however after a system update to Kernel 3.15.10 there is no longer output on the hdmi port.

I talked about this yesterday on the #fedora-arm irc channel. The problem is that the tegra_drm module is not added to initrd.

Manually running "modprobe tegra_drm" restores the output on the hdmi port.

When I asked about the cause of this, I got this reply:
[Thursday 04 September 2014] [18:56:32] <nchauvet> issue with the way dracut detect the drm driver, fixed in f22 dracut

Fedora 22 is still a long way ahead of us. So would it be possible to backport this fix to Fedora 20 ?
Comment 6 Nicolas Chauvet (kwizart) 2014-09-05 10:19:03 UTC 
(In reply to info from comment #5)
..
> I talked about this yesterday on the #fedora-arm irc channel. The problem is
> that the tegra_drm module is not added to initrd.
The autoloading of the tegra_drm is fixed with backport of:
ApplyPatch arm-tegra-drmdetection.patch
that is currently available on kernel 3.16.
This kernel should hit f20 updates at some point.
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