Hi, On Sun, Feb 26, 2017 at 2:48 AM, Samuel Thibault <samuel.thibault@xxxxxxxxxxxx> wrote: > Samuel Thibault, on dim. 26 févr. 2017 02:50:05 +0100, wrote: >> Please note in your todo for the input part, that ttyio will have to >> call read_buff_add for each received character, when that method is >> not NULL (that's actually the only driver using it, so we will really >> need a tester for this exact driver). > > More precisely, it's the spk_ttyio_ldisc_ops->receive_buf2 method which > should call read_buff_add for each received character. > > > The step further will be implementing spk_ttyio_in and > spk_ttyio_in_nowait. I believe the easiest way is the following: > > - define an spk_ldisc_data structure containing just one character (buf), > and a semaphore. > > - on ldisc_open, allocate a pointer to such structure, set > tty->disc_data to point to it, and initialized the semaphore to 0 > tokens. > > - in the receive_buf2 method, > - if read_buff_add is defined, just call it for each character and be > done > - otherwise, store the first received character in > ((struct spk_ldisc_data *)tty->disc_data)->buf > , call up() on the semaphore, and return 1 (to tell that you ate the > character). I don't fully understand how the return value of receive_buf2 is used in flow control. According to Documentation/serial/tty.txt it is the number of bytes processed by it, whereas comments on top of tty_ldisc_receive_buf function's definition - which returns value returned by receive_buf2 - say it is the number of bytes not processed. Also, is the call to tty_schedule_flip in spk_serial_in because we returned 1 receive_buf2 so we have to manually tell it to flip buffer? Thanks, Okash _______________________________________________ Speakup mailing list Speakup@xxxxxxxxxxxxxxxxx http://linux-speakup.org/cgi-bin/mailman/listinfo/speakup
