Hi all, I have a lot of linux computers equipped with a GlobalSat Br-353 GPS receiver, which is connected via USB (an integrated PL2303). The GPS receiver emits one multi-line message every second, giving position and time. I listen to this messages in a user program running in the highest priority, and I have noticed that under load, the messages are not delivered to my process every second, but often delayed, which is not great for a time source. I looked at the sources of pl2303 and added a diagnostic message if the beginning of a message came more than one second later than the beginning of the previous one, and I noticed that the delay was already present in the kernel: often even more than one second delay after the expected beginning time. Can you give me some advice on how to avoid that delay ? How can I increase the polling priority of this serial line, or how may I get some usefull debugging about the USB polling for this serial line ? Thanks in advance Philippe -- 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
