Did PCI/IRQ allocation change significantly after 4.2 kernel?

From: rgroner@rtd.com (Rob Groner)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Did PCI/IRQ allocation change significantly after 4.2 kernel?
Date: Tue, 29 Mar 2016 11:27:49 -0400	[thread overview]
Message-ID: <1459265269.2010.7.camel@rtd-VirtualBox> (raw)
In-Reply-To: <20160329144314.GA24237@kroah.com>

On Tue, 2016-03-29 at 07:43 -0700, Greg KH wrote:
> On Tue, Mar 29, 2016 at 07:42:44AM -0700, Greg KH wrote:
> > On Tue, Mar 29, 2016 at 02:15:23PM +0000, Rob Groner wrote:
> > > I?m investigating why our drivers no longer work correctly after the 4.2
> > > kernel.  I have verified that in the 4.4 kernel, interrupts no longer work for
> > > us as they did before.  Here are the symptoms:
> > 
> > What drivers are these?  Do you have a pointer to the source for them?
> > 
> > And what platform are you having these problems on, x86, arm64,
> > something else?

x86 only (we don't support other platforms).  An example of the code
(this problem appears to be affecting all of our drivers so far) is on
our website.

http://www.rtd.com/software/DM/DM35x18/DM35418_Linux_v03.00.00.tar.gz

If you end up looking at the driver code, I apologize in advance for all
of the obvious errors you might find.  It's a little intimidating having
one of the authors of LDD look at your code... I feel like I didn't
study hard enough for this.  

> Also, can you use 'git bisect' to find the problem commit?  That might
> be the easiest way forward.

Umm...yes!  As soon as I figure out what that means.  I'm a git newbie
(we use svn), but I shall learn as quickly as I can.  I take it that it
basically means "start with a kernel that worked and then start moving
forward through commits until I find the one that broke", right?

Rob