HI Alan: It helped; thanks much. I notice there are 2 ioctls for reapurb (with and without timeout).
-ashili --- Alan Stern <[EMAIL PROTECTED]> wrote: > On Sun, 26 Mar 2006, ashili wrote: > > > I am using devio.c interface to talk to usb > device. I > > cannot make the SUBMIT_URB for bulk-in endpoint > work. > > Here is what I am doing in my user space app. > > ---Open devnode, read descriptors, send ioctl for > "set > > configuration", I get the return values 0 > (success). > > ----Set the realtime signal hander for > "submiturb", > > and issue ioctl "submiturb" for bulk-out endpoint > with > > data. Signal handler gets invoked with status bit > > field set to 0 (success) and I suppose it also > means > > this transaction is complete. And I notice via bus > > tracer that data is moving to the device. > > So you know all that works correctly, which is a > good start. > > > ---Now issue, "sumbiturb" ioctl for bulk-in > endpoint > > (I know my device has data to send back). Signal > > handler gets invoked with status bit field set to > > 0(success), > > What do you mean by "status bit field"? The actual > status is reported in > the struct siginfo's si_errno field. Is that what > you are checking? > > > but the user level buffer (which is sent > > as parameter to usbdevfs_urb) is empty. Also, I > notice > > in the bus trace that there is no data(or zero > data) > > coming from device to host. This tells me I am not > > issuing submiturb right. > > Not really. If there were a failure in submitting > the URB then your ioctl > call would return directly with that error code and > the signal handler > would not get invoked. > > > I wanted similar to asynchronous support and > hence I > > cannot use the ioctl "USBDEVFS_BULK". Is there any > > other setup I should do to make "sumiturb" ioctl > > work? or should I issue any other ioctl in between > or > > from within signal handler(I cant understand if > the > > ioctls "setinterface" and "reapurb" has any > relevance > > to this context). > > setinterface almost certainly doesn't. It issues a > Set-Interface request > to your device (chooses an altsetting). > > At some point you have to do a reapurb so that the > system can release the > resources associated with the URB. You should do it > before resubmitting > this URB, but you can submit another URB before > reaping this one. > > > It seems this is a basic question(I cant find > answer > > in archives). > > > > how can I get data from device using "submiturb" > > ioctl? Thanks in advance for the response. > > You'll find that it helps to build your kernel with > CONFIG_USB_DEBUG > enabled. Then there will be lots of useful > information in the kernel log. > Also, even if you don't have CONFIG_USB_DEBUG turned > on you can still use > the usbfs_snoop=y module parameter for usbcore.ko to > get logs of all your > usbfs transactions. > > Alan Stern > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
