Messages in this thread |  | | From | David Laight <> | Subject | RE: [PATCH 3.12 033/118] usb: xhci: Link TRB must not occur within a USB payload burst [NEW HARDWARE] | Date | Fri, 17 Jan 2014 14:34:07 +0000 |
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From: walt > Oy, Sarah! ;) I put the ASMedia adapter in my older amd64 machine, and, well, > the stupid thing Just Works(TM) with kernel 3.12.7! (Yes, with the same disk > docking station, too.) > > I can't believe the adapter works perfectly in a different computer. Have you > seen this kind of thing before?
Could be a horrid timing race between the cpu and xchi controller. If the cpu manages to write a NOP or LINK TRB for a following transfer before the controller polls the next entry (after raising the IRQ) then the controller might process the LINK and then get confused when it can't process the linked-to TRB. This might not sound likely, but PCIe has significant latency.
> At the moment I have two machines using your xhci driver and both work perfectly, > so I thank you again :) > > I'm not sure where to go with this next. I could put the adapter back in the > other machine again if you have more patches to test.
Can you try the patch I posted that stops the ownership on LINK TRBs being changed before that on the linked-to TRB?
I got a private mail from someone indicating that my earlier 'minimal' patch helped an ASMedia controller talking to the asx189_178a ethernet hardware.
David
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