On Fri, Sep 06, 2013 at 12:06:21PM -0400, Tejun Heo wrote:

Hello, Bjorn.

On Fri, Sep 06, 2013 at 10:01:38AM -0600, Bjorn Helgaas wrote:

quoted

Sorry, I haven't jumped in here yet because I saw your discussion and
was hoping you guys would figure something out without my help.  It
will take me a few hours to look into this and come up with anything
constructive to say.

I do remember disliking the complicated interface of
pci_enable_msi_block() (return negative errno, return positive "we
might be able to do this" values, or zero), but I'll have to do some
more research before I can say much more than that.

According to Alexander, it doesn't even seem like we have any actual
use case for the positive return numbers.  I say just rip it out and
do the regular 0/-errno all the way through.

I agree, that would be much simpler.

I propose that you rework it that way, and at least find out what
(if anything) would break if we do that.  Or maybe we just give up
some optimization; it would be nice to quantify that, too.

Bjorn