On Fri, 11 Jan 2008, Pandita, Vikram wrote: > On Kernel 2.6.24, > I am trying Suspend/Resume on OMAP3430 EHCI controller with Netchip2280 High > speed test device. > > Following is the behaviour: > > #echo suspend > /sys/bus/usb/devices/2-2/power/level > # suspend root hub > > On the bus, SOFs stop and device goes to Suspend [As expected] > > #echo on > /sys/bus/usb/devices/2-2/power/level > > Rarely resume happens fine and most of the times I get the following error: > > GetStatus port 2 status 001005 POWER sig=se0 PE CONNECT > devpath 2 ep0in 3strikes > devpath 2 ep0in 3strikes > devpath 2 ep0in 3strikes > usb 2-2: USB disconnect, address 2 > # port 2 full speed --> companion > GetStatus port 2 status 003801 POWER OWNER sig=j CONNECT > GetStatus port 2 status 003002 POWER OWNER sig=se0 CSC > suspend root hub > > > 1) Why is the device handed over to the Full Speed controller on a resume > most of the times?
The device is handed over because the EHCI hardware tells the kernel that the device did not respond with a high-speed "chirp" during the reset sequence. Why does the EHCI hardware do this? There are two possible reasons. Either the device really does fail to send the high-speed chirp, or else the chirp is sent and the EHCI hardware doesn't recognize it. Why does this happen only most of the time? I have no idea. What do you get if you test a different high-speed device? > 2) Refer: Documentation/usb/ehci.txt > > There are some issues with power management; suspend/resume doesn't > > behave quite right at the moment. > Is this related to the above problem? Probably not. That file is rather out-of-date. Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
