On Fri, 13 Aug 2010, Dennis Nezic wrote: > My usb2.0 multi-card reader, 058f:6366 Alcor Micro Corp., with vanilla > kernel 2.6.35.1, doesn't seem to work with ehci_hcb. It does work with > ohci_hcb, so I don't think it's a hardware problem necessarily? > > Here is my syslog when using EHCI: > http://dennisn.dyndns.org/guest/pubstuff/ehci-bug/ehci-fails.log > > Here is my syslog when using OHCI: > http://dennisn.dyndns.org/guest/pubstuff/ehci-bug/ohci-works.log > > The main differences that I notice are many "detected XactErr"s with > ehci, but they don't seem to be too critical, until they (seem to) > cause: > > 09:14:30 kernel: ehci_hcd 0000:00:13.2: devpath 8 ep2in 3strikes > 09:14:30 kernel: usb-storage: Status code -71; transferred 76288/98304 > 09:14:30 kernel: usb-storage: -- unknown error > 09:14:30 kernel: usb-storage: Bulk data transfer result 0x4 > 09:14:30 kernel: usb-storage: -- transport indicates error, resetting > > ... which seems to happen with "usb_stor_bulk_transfer_sglist: xfer" > greater than about 512 bytes? (The transfers seem to complete with > smaller xfers?) > > Ideas? Suggestions? You probably have a bad electrical cable connection. It's good enough to work at full speed with OHCI, but it's marginal at high speed with EHCI. You get occasional errors, and eventually the errors become too numerous for the system to handle. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
