On 08/06/2015 04:32 PM, Yinghai Lu wrote:
On Thu, Aug 6, 2015 at 9:18 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
On 08/06/2015 08:58 AM, Yinghai Lu wrote:
Ok, I admit that I am lost. Earlier it seemed that you were concerned about
this case, where no io window is available or a bus doesn't support io,
but a non-transparent child does. Now you seem to say that the
non-transparent
child would not be able to support IO either.
For my education, can you list the possible options, and how you suggest
to solve them ? I can see the following situations.
- root supports IO, but has no io window assigned
- root does not support IO and has or has not an IO window assigned
- a bridge does not support IO
should have two cases:
1. root bus does not have io window exposed.
2. pci bridge io bar is not writable.
For the transparent case, each of those should result in all children
not even trying to assign an IO window, which is what we want,
and what my patc set tries to do.
How should those cases be handled for non-transparent bridges ?
for case 2: current upstream code, no warning for the bridge itself,
but have warning for devices under the bridge.
That warning is what I am trying to get rid of, because it is repeated
dozens of times with zero value.
We only need to handle case 1, aka root bus does not have io port window.
What about your setup, is it case 1 or case 2?
Assuming case 1) includes case 3), root bridge does not support IO,
I have both case 1 and 2.
Anyway, I think I am giving up. Sorry, I just fail to understand the
use case(s) you are trying to cover.
Why don't you submit a patch, I'll test it if it works for my use
case, and if it works we ask Bjorn to apply it. My problem is quite
simple: I don't want to get flooded with useless "no IO window" messages.
How it is solved doesn't matter to me, as long as it is solved.
Since you have a strong opinion on how it should be solved, we should
go with your solution and not keep turning in circles forever.
Thanks
Guenter
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