On Wed, May 12, 2010 at 11:50:52AM -0700, Ron Madrid wrote: > I'm trying to transfer data across a USB port via g_serial > (on gadget side) and cdc_acm (on host side) but I'm seeing > some strange behavior and I want to get some advice on where > I can start looking. This is on an MPC8313 based system > running the latest kernel. > > I have written a pair of applications that open each device > (ttyGS0 and ttyACM0) and transfer data back and forth. > However when I'm running the apps the gadget side will send > (or think it sent) all appropriate data to the host side, > but the host will only receive part of the transmission and > time out in the select() call. I am not seeing any errors > from the gadget side kernel but occasionally this will lock > up my host system. Small data transfers of around 200 bytes > or less seem to work fine, but when I try larger transfers > (1k or greater) I will see it fail (timeout in select()). > > I know that my data transfer 'protocol' works as it works > great over ethernet and fsl-usb2-udc seems to work fine also > as I can do this using g_ether, but I'm not sure whether > this is a problem within g_serial, its interface with > fsl-usb2-udc, or my setup of the tty device in the > applications. I've tried a ton of different configurations > with the termios structure but haven't seen this work > reliably. > > Thanks for your feedback and let me know if you need more > information about the problem. What kernel version are you using? If you use usbmon to monitor the data, do you see everything flowing properly? thanks, greg k-h -- 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
