On Tue, 12 Jun 2012, Austin Schuh wrote: > On Tue, Jun 12, 2012 at 7:01 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > If you enable CONFIG_USB_DEBUG, you can go into the appropriate > > subdirectory of /sys/kernel/debug/usb/ehci and see what the various > > files there contain. > > > > Good to know, thanks! I'm now reading up on what the data from the > async file means. > > $ cat /sys/kernel/debug/usb/ehci/0000\:00\:1a.7/async > qh/ffff88047452a700 dev8 hs ep2 42002208 40000000 (80008c00 data1 nak4) > ffff880037801180 out len=0 80008c00 urb ffff880596b06600 This means that the transfer was completed but the computer apparently never got a completion interrupt. > $ cat /sys/kernel/debug/usb/ehci/0000\:00\:1a.7/lpm > $ cat /sys/kernel/debug/usb/ehci/0000\:00\:1a.7/periodic > size = 1024 > $ cat /sys/kernel/debug/usb/ehci/0000\:00\:1a.7/registers > bus pci, device 0000:00:1a.7 > EHCI Host Controller > EHCI 1.00, hcd state 1 > ownership 00000001 > SMI sts/enable 0xc0080000 > structural params 0x00103206 > capability params 0x00016871 > status 8008 Async FLR > command 0010021 (park)=0 ithresh=1 Async period=1024 RUN > intrenable 37 IAA FATAL PCD ERR INT > uframe 3f17 > port:1 status 001000 0 ACK POWER sig=se0 > port:2 status 001000 0 ACK POWER sig=se0 > port:3 status 003000 0 ACK POWER OWNER sig=se0 > port:4 status 001005 0 ACK POWER sig=se0 PE CONNECT > port:5 status 001000 0 ACK POWER sig=se0 > port:6 status 001000 0 ACK POWER sig=se0 > irq normal 43424 err 0 reclaim 6314 (lost 21) > complete 43440 unlink 3819 That's pretty normal, except that the count of lost IAA interrupts ought to be 0. If you get rid of the line saying: ehci->need_io_watchdog = 0; under the PCI_VENDOR_ID_INTEL case in drivers/usb/host/ehci-pci.c:ehci_pci_setup(), it may help. This isn't supposed to be necessary; Intel components are pretty reliable. 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
