On Fri, Dec 18, 2009 at 4:44 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > By contrast, the "OHCI 1.0" value comes directly from the hardware. As > far as I know there is no OHCI-1.1 standard, so it's not surprising > that the device only claims compatibility with OHCI-1.0. Yes, I have mixed OHCI revision with USB revision, sorry :). > No. It results from the value of the NPS bit in the hardware > HcRhDescriptorA register. If value of NPS is 1 then you get that "no > power switching" message. If you want to enable power switching, you > might be able to do it by editing ohci-sa1111.c: Make it clear the NPS > bit. I have cleared it but it still reports this way. This cannot be the cause of communication problems however, can it? > You should post some usbmon traces. You should also get a stack trace > (Alt-SysRq-T) to find out where rmmod hangs. And you should check out > the contents of the debugging files under > /sys/kernel/debug/usb/ohci/0400/. To do this effectively I need to learn more about USB. For now I have only sysrq-t result: http://filip.eu.org/jornada/usb_host/dmesgs/rmmod_trace.txt I will dive into it soon. In the meantime I have followed a suggestion from mkl lin <mkl0301@xxxxxxxxxxx> to disable d-cache: > I did it. I prepared a minimal kernel with this config: > http://filip.math.uni.lodz.pl/jornada/usb_host/dmesgs/kernelconfig > I ran two test sessions. One with d-cache enabled, and one with > d-cache disabled. > > Tested device was connected before booting. > Testing with d-cache disables was a royal PITA, because it tends to > freeze in random moments and > reboot procedure of the jornada is a bit painful (running through > wince dialogs). > > I have placed logs from various tests here: > http://filip.math.uni.lodz.pl/jornada/usb_host/dmesgs/ > > It seems to go further with device initalisation without d-cache. It > can even sometimes bind a driver > to a device: > http://filip.math.uni.lodz.pl/jornada/usb_host/dmesgs/without_d_cache/mouse.txt > http://filip.math.uni.lodz.pl/jornada/usb_host/dmesgs/without_d_cache/gps-5.txt > > and works a bit with a hub: > http://filip.math.uni.lodz.pl/jornada/usb_host/dmesgs/without_d_cache/hub-pendrive-mouse-3.txt > > I am not sure this is a problem with cache handling or maybe it does > better because of a massive slowdown > (4 bogomips instead of 140). Is this a valuable trace? regards, Filip Zyzniewski -- 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
