> I remember removing the low_latency flag to 0 once & if I recall correctly performance > was severely impacted & there may have been other problems which I don't recall. The modern buffering and old buffering are rather different so that shouldn't be a problem. > Now tty_insert_flip_string can return 0 bytes leading to an infinite loop if tty buffers are full, > as write_length_remaining never goes to zero as I am dependent on the line > discipline being called from tty_flip_buffer_push to set TTY_THROTTLED by calling flush_to_ldisc In all cases tty_insert_flip_string may return 0 for other reasons (eg out of memory). > checking if curr_write_len=0 from tty_insert_flip_string might fix the problem > Please look at put_rxbuf_data carefully, there might be other gremlins. The serial port > is supposed to be high performance this fix will impact this Will do, but it should have no impact at all on throughput - in fact it ought to improve it. You can't call tty_flip_buffer_push() from an IRQ handler with tty->low_latency set anyway... -- 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
