Messages in this thread | | | Date | Thu, 13 Aug 2009 11:15:21 -0700 | From | Greg KH <> | Subject | Re: [PATCH] Combine two one-character CR-LF writes into one two-character write for O_ONLCR |
| |
On Thu, Aug 13, 2009 at 10:54:30AM -0700, David VomLehn wrote: > When handling output of a newline character in O_ONLCR mode, the n_tty.c > do_output_char() function uses the struct tty_operations function write_room() > to determine whether it is possible to write two characters. It uses > tty_put_char() for each character which, for the USB generic serial driver, > translates into a write() for each character. For the USB generic serial > driver the value returned by write_room() only applies to the next write(). > A second write() done in quick succession will fail because the write URB > buffer is still busy from the first write(). In this case, it results in the > printing of a carriage return without the following line feed.
How about fixing the usb-serial generic driver to properly handle stuff like this instead? It should be using a fifo and not the stupid method it currently is.
Anyway, what device are you using that uses the usb-serial generic driver that you are seeing this problem with?
thanks,
greg k-h
| |