On Mon, 22 Aug 2005, Savita H wrote: > Hi All, > > I need to write Linux driver for USB Scanner device on fedora core4 Os. that > is 2.6.11 kernel. > > Scanner device has three endpoints, one is Bulk-out (ep->EndpointAddress = > 0x02) and two bulk-in ednpoints ( 0x84 and 0x86). > i need to send commands on bulk-out endpoints. I have allocated memory for > this by kmalloc(), then allocated and filled URB as follows...
> The return value of usb_submit_urb shows, it has submitted the URB > successfully, but the scanner shows no responce for that command, > ex: i am sending command to turn the LED ON, which is not happening. > > before submitting this URB, i have submitted both bulk-in URBs, these URB's > call back functions are not at all called when the scanner has to respond to > some commands sent to it on bulk-out EP( like firmware version no). > > Why is this happening? Scanner has responded for version no and LED ON, only > once or twice in one months effort, after that no responce. the same code > worked for few minutes well and its not working now. why? > > i have also tried to allocate memory for bulk out using usb_alloc_buffer and > seeting transfer_flags to URB_NO_TRANSFER_DMA_MAP, but no result. NO idea of > whats happening!!!!!! > > Any sort of help or inputs will be greately appreciated. > Thanks in advance. > Savita It's possible that some other program is also communicating with the scanner, and the scanner is being confused by the combination of commands. To see what's really going on, you could use the "usbfs_snoop=y" module parameter for usbcore and you could use the usbmon facility. Alan Stern ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
