On Sun, Nov 29, 2009 at 09:20:13AM -0800, Jason Byrne wrote: > On Sun, Nov 29, 2009 at 8:28 AM, Matthew Dharm > <mdharm-usb@xxxxxxxxxxxxxxxxxx> wrote: > > On Sun, Nov 29, 2009 at 10:45:16AM -0500, Alan Stern wrote: > >> On Sun, 29 Nov 2009, Jason Byrne wrote: > >> > >> > Hi, > >> > > >> > I've tried several stable kernel versions with an isd200 usb2 cradle, > >> > and it seems that the last working kernel version with this device may > >> > be 2.6.26.8. > >> > > >> > I'm not sure if this was related to the separation of the isd200 > >> > driver into a separate module, or if it's an ehci_hcd issue, or what > >> > the cause is... > >> > >> You should collect a pair of usbmon traces, one from a working kernel > >> and one from a recent non-working kernel. See > >> Documentation/usb/usbmon.txt for instructions. > > > > It looks like the working version doesn't use high-speed, only full speed. > > Try rmmod'ing ehci_hcd on the newer kernel and then attaching the device. > > It does work if I rmmod ehci_hcd and attach the device, but using usb > 1.1 for this device would be a huge step backward. Historically, there > was a usb 1.1 version of this particular cradle that may also use an > isd driver, but I've used this particular cradle for years with usb > 2.0/high speed. It may be a huge step backwards, but it is also a significant datapoint for debugging. Specifically, the usb-storage driver does not have any codepaths which differentiate between full-speed and high-speed devices. This makes it likely that this is an EHCI-related issue. Matt -- Matthew Dharm Home: mdharm-usb@xxxxxxxxxxxxxxxxxx Maintainer, Linux USB Mass Storage Driver P: Nine more messages in admin.policy. M: I know, I'm typing as fast as I can! -- Pitr and Mike User Friendly, 11/27/97
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