On Sun, 2015-09-06 at 17:44 +0300, Michael S. Tsirkin wrote:

quoted

quoted

My question is: is necessary to initialize MSI capabilities even with
CONFIG_PCI_MSI not set? In negative case, would be "cleaner" revert the 3
commits, right?

quoted

I think the reason why it's necessary is explained in
commit log for commit 1851617cd2da9cc53cdc1738f4148f4f042c0e56 (that's
[3] below).

Thanks very much Michael. I re-read the text of your commit, and makes 
sense then to initialize the MSI capabilities even with CONFIG_PCI_MSI 
not set.

On 09/07/2015 12:17 AM, Michael Ellerman wrote:
Well yes and no.

What we want to do when CONFIG_PCI_MSI=n is disable MSI on the device. In order
to do that the code first initialises dev->msi[x]_cap.

But arguably that's wrong, ie. when CONFIG_PCI_MSI=n dev->msi[x]_cap *should*
be zero so that any code which erroneously tries to use them will fail.

But perhaps that's being too pedantic :)

I thought exactly this - that was the reason of my questioning. Thanks 
for your opinion Michael - I'd call the argument logical, not pedantic 
hehehe


Cheers