RE: [PATCH 0/9 v7] xHCI: Isoc transfer implementation

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> -----Original Message-----
> From: Sarah Sharp [mailto:sarah.a.sharp@xxxxxxxxxxxxxxx]
> Sent: Wednesday, July 14, 2010 2:44 AM
> To: Xu, Andiry
> Cc: linux-usb@xxxxxxxxxxxxxxx; gregkh@xxxxxxx
> Subject: Re: [PATCH 0/9 v7] xHCI: Isoc transfer implementation
> 
> On Fri, Jun 25, 2010 at 04:48:37PM +0800, Andiry Xu wrote:
> > Hi Sarah,
> >
> > This is xHCI isoc transfer implementation patchset v7.
> >
> > Changelog from v6:
> > 1. Break the xHCI: handle_tx_event() refine patch into six smaller
> > patches.
> >
> > Again, this patchset is based on revert-link-trb branch,
> > commit 5162708fc3c0.
> 
> I assume you based your work off the revert-link-trb branch because
you
> ran into issues with overwriting the link TRBs when queueing
isochronous
> transfers.  However, the patches on that branch are not going to be
> merged.  They were just a quick test to see if the link TRB change was
> an issue for someone.
> 
> The patches to fix the known bugs in the link TRB handoff change from
> John have been sent to Greg, and one has already been sent out by
Linus.
> I don't want to revert John's patch, as it's needed for streams
> communications to work properly.  So you're going to have to add a
patch
> to work around the isochronous issues with John's patch.
> 
> I think the patch will be similar to the control transfer fix (commit
> 6cc30d85a5bf61248ff0e1f0e0f15fe718bae378 in Linus' tree).  Basically,
> you need to indicate to queue_trb() whether more TDs are coming if
> you're going to queue multiple isochronous TDs without calling
> prepare_transfer() in between each TD.
> 

Thanks for the information, I'll rebase the patchset on your master
branch. I've checked the control transfer fix, but I wonder what you
mean by saying that I do not to need to call prepare_transfer() for each
TD? As I can see, the prepare_transfer() do initialization for each TD,
add it to the ep's ring, which is necessary for each TD. Does the
control transfer fix affect prepare_transfer() calling? I don't quite
understand.

> I've updated my master branch to be against 2.6.35-rc4, with some
> additional bug fixes that Greg has queued.  Can you please base your
> next patch set against that?  I'll send more comments on the isoc
> patchset later today so you can do the changes all at once.
> 

Thanks. I'll refine the patches and do another 24-hour stress test
before resubmit.

I got another question. When I'm debugging the PM patches, I found that
when hub driver disable a USB3 protocol port and then reset the port, it
will transition to a USB2 protocol port. This will affect USB3 device
re-initialization during S3 resume. Is this normal behavior? If I do not
disable the USB3 protocol port, the USB3.0 device will be recognized
normally later.

Thanks,
Andiry


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