Hi Joey, On Tue, Aug 30, 2011 at 05:59:49PM -0400, Joey Oravec wrote: > Dmitry - > > In serio_raw.c function serio_raw_write() there's a check: > > if (count > 32) > count = 32; > > which coerces any call to write a maximum of 32 bytes. Do you know > why this limitation is in the code? Characters get written > one-by-one to the tty layer so I don't understand why it's there. The driver was trying to mimic behavior of 2.4 psaux device as close as possible so 32 bytes limit came from there. Besides I think it is a good idea to not allow one process hog serio port for too long... > > I'm not sure which section of the manpage defines write for a serial > port. In the ordinary case I expected this function to keep > transmitting until complete or an error occurs. If O_NONBLOCK was > specified then I might expect EAGAIN. Right now my calling code > doesn't expect a successful partial write. Do you think this module > is doing the right thing? Can you comment on what the caller must > expect? I think you should handle partial writes. Even if driver honored O_NONBLOCK you could get a partial write and not necessarily EAGAIN. May I ask you what you are using serio_raw for? Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
