Re: pci adapter not working in dom0. works under plain Linux.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Jun 11, 2014 at 02:12:13PM +0200, Sander Eikelenboom wrote:
> 
> Wednesday, June 11, 2014, 1:53:48 PM, you wrote:
> 
> >> 
> >> > I had some preliminary patches for the V4L API to use a better
> >> > DMA ops, but I fear that they are bitrotten (and I can't even
> >> > find them!). But lets try first determine if the workarounds
> >> > work for you.
> >> 
> >> Were you by any means referring to this thread / patch:
> >> http://lists.xen.org/archives/html/xen-devel/2012-01/msg01982.html ?
> >> 
> 
> > That patch applies and compiles once you take into account some moved files. I haven't tested yet though - my mythtv box is busy recording :)
> > I notice there is a 'videobuf2-dma-sg.c' file in the current tree, which I assume is a 'second generation' v4l implementation that drivers will be progressively moved over to. I can't tell if the dma implementation in there is correct, but it certainly doesn't return any hits in a grep for 32...
> > A grep for the export 'vb2_dma_sg_memops' only shows up 2 drivers using it though. What's the procedure around rebasing and submitting a patch that someone else wrote?
> 
> Yeah the conversion is going slowly .. i tried to start it for the cx25821 .. 
> but the problem is it's "all or nothing" you can't do it in little steps.

You mean the patch I wrote that I totally forgot about until
Sander awesomely found it? You can go ahead and have it come
from you (aka, the author can be you). The only thing I would
ask you to keep is my SOB (so it is known that it came through
my hands) in the patch and maybe mention: "Rework of Konrad's initial
patch" (optional).

You should not treat this as a general rule though - but the yardstick 
I've done is - contact the author of the patch - ask them if they are OK
with the patch and me reworking it. If they don't respond or are unreachable
I take the ownership of the patch and start reworking. At that point
I just make sure that I keep their original Copyright in the file or mention
it as an SoB.


> 
> > I think Konrad's fix is the right way to go. Someone else suggested fixing vmalloc32, which is probably still a good idea, but when most of the devices these days are probably quite happy with 64 bit addresses so sticking with the artificial 4G limit is probably a bit silly.
> > I'll follow up once I've tested later tonight or tomorrow.
> 
> > Thanks!
> 
> > James
> 
> 
>