Bug 186520

Summary:	CONFIG_PCI_MSI is not set to y in installed x86_64 2.6.15 kernel for fc5
Product:	[Fedora] Fedora	Reporter:	Dave Olson <dave.olson>
Component:	kernel	Assignee:	Dave Jones <davej>
Status:	CLOSED ERRATA	QA Contact:	Brian Brock <bbrock>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	5	CC:	bos, lindahl, pfrields, rjwalsh, wtogami
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:	2006-07-16 01:44:34 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Dave Olson 2006-03-24 00:50:50 UTC

As installed, the .config does not have MSI enabled.   It was
enabled for FC4 and FC3 kernels.  I can't find any reason in
the release notes or lkml for it being disabled.

Our PathScale InfiniPath product requires MSI in order to function,
and I was surprised to find that I had to install the kernel source
rpm and reconfigure in order for MSI to function.

Was this a deliberate change, and if so, what was the reason?

Comment 1 Dave Jones 2006-03-24 22:42:47 UTC

It caused problems booting on some systems.  I don't have the details to hand.

Comment 2 Bryan O'Sullivan 2006-03-27 23:16:15 UTC

This is a big problem for us.

Comment 3 Greg Lindahl 2006-03-31 20:52:23 UTC

1. Our cards are the first of probably many which require MSI. MSI was optional
for PCI-X but is required for PCI Express.

2. Other cards like the Mellanox InfiniBand adaptor run faster with MSI enabled
-- see the OpenIB mailing list for discussion about this a while ago.

I have no doubt that some systems have problems with MSI, but they're broken and
will probably get fixed, for example I spent 2 days arguing with the in-house
BIOS team at a Tier 1 computer vendor (a big Red Hat partner) and they finally
agreed that they needed to fix their BIOS so that MSI worked. It turned out to
be a one-line fix...

Comment 4 Dave Olson 2006-04-03 17:38:43 UTC

It appears that the latest FC 4 2.6.16 kernel now has the same issue, that
is, the default 2.6.16 kernel with FC4 yum update now has CONFIG_PCI_MSI=n

Comment 5 Dave Olson 2006-05-09 05:58:25 UTC

It appears that the latest fc4 update kernels (e.g. 2.6.16-1.2108_FC4smp for
x86_64) now has CONFIG_PSI_MSI=y again, and I'm told FC5 has also reverted
to enabling this.   Should we expect that to remain true for future 
Fedora kernels?

Comment 6 Dave Jones 2006-05-09 23:59:35 UTC

no (it was on as an experiment in fc4, and sneaked into an update
inadvertantly), I'm going to look at enabling it across the board when I rebase
to 2.6.17