RE: PROBLEM: USB isochronous urb leak on EHCI driver
From: Michael Tessier <hidden>
Date: 2015-02-09 23:21:48
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That is interresting, however, I have an older kernel running=20 an OHCI driver which is able to handle 4 codecs. Same usb=20 hardware (codecs and hub), but older kernel on a different=20 CPU, with much less power. This makes me believe that there's a=
solution to make it work...
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=20 Of course there is: Install an OHCI host controller and use it to=
drive your codecs. It should work fine.
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=20 What do you mean by that? The host controller is embedded in the i.MX C=
PU...
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Changing the CPU is not really an option to me. Unless I am missing=20 something?I didn't realize you were talking about an i.MX-based system. On a compu=
ter with a free PCI slot, it's easy to add an OHCI controller. =20
iMX isn't as accomodating. If there's no way to add an extra USB controller to your system then the =
only choice is to upgrade the driver software.
Alan Stern
Okay; I did my homeworks. We've loaded kernel V3.16 (Oct 14th, 2015) on an = i.MX51 plattform and the problem is still there. Unless an important change= occured in V3.19, it appears that the latest kernel is not the solution fo= r us. So we're still not able to use 4 codecs on our i.MX plattform. So just to make things clearer: - We have customers waiting for a solution with that hardware (this hardwar= e is already delivred AND used); - We have important comittments and severe penalties ($$$) if we're not abl= e to deliver on time (due for March 15th); - We've already looked at a hardware solution, which corresponds to replace= current units ($$$$$), so that is not really an option for us; So as a last resort, I'm wondering, where is the USB expert who could help = us solving our problem? Any suggestions? If we are to get into debugging the USB driver, we would do it with the cur= rent kernel used (V2.6.31). What are the better tools to get into that? I g= uess a USB analyzer (hardware) would be the smart thing? Any brand name to = suggest? Any other ideas for a solution will be really appreciated. Regards, Michael Tessier.