Bug 706443

Summary:	HP 6730b Intel Graphics driver problems
Product:	[Fedora] Fedora	Reporter:	Joshua Knarr <josh.knarr>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	low	Docs Contact:
Priority:	unspecified
Version:	14	CC:	gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-05-21 12:27:32 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description Joshua Knarr 2011-05-20 15:26:52 UTC

Description of problem:
Here at work we use HP 6730b laptops with the intel graphics drivers. When the machines boot they are fine until they actually go to use the X display, at which point X becomes choppy. Eventually the kernel module crashes with:

Package:    	kernel
Latest Crash:	Fri 20 May 2011 11:12:32 AM 
Command:    	not_applicable
Reason:     	WARNING: at drivers/pci/intel-iommu.c:1988 iommu_prepare_identity_map+0x153/0x198()
Comment:    	None
Bug Reports:	

After this happens, the X display becomes smooth and responsive. While this problem does not happen every time X is started, it happens the majority of the time. The workaround is to switch to another console (CTRL+F2 or whatever) and switch back. This usually either forces the crash or magically fixes the problem. 

Version-Release number of selected component (if applicable):
Fedora release 14 (Laughlin)
Linux barley.laptop.com 2.6.35.13-91.fc14.x86_64 #1 SMP Tue May 3 13:23:06 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

How reproducible:
Boot the laptop. This happens consistently across all the 6730bs here running fedora. The ubuntu guys don't seem to have the problem. Our lone SuSE person does have the problem.

Steps to Reproduce:
1. Start laptop. Display will become choppy at GDM
2. Switch to VT, switch back
3. If display is still choppy, repeat step 2 until the crash warning appears and display is happier.
  
Tags: CommonBugs

Comment 1 Chuck Ebbert 2011-05-21 12:27:32 UTC

Did you read the rest of that message?

  Your BIOS is broken; RMRR exceeds permitted address width

Turn off virtualization in the BIOS or add "intel_iommu=off" to the kernel boot options.

Comment 2 Joshua Knarr 2011-05-21 13:31:13 UTC

Chuck,

Thanks for the help.

That is actually the full text of the error - I opened the ticket by choosing "copy to clipboard" from the crash report applet. If there's supposed to be more, it would help the users if it displayed the whole thing. ;)

I tried it with "virtualization technologies" disabled in the BIOS and with the kernel parameter set and I get the same results. It just did it after setting intel_iommu=off. 

I will ask HP when they're updating their BIOS, this BIOS for this notebook (HP 6730b) is current. Googling for IOMMU set me in the right direction - looks like this is a common problem with Centrinos + HP.

Thanks again,
Joshua Knarr