Date: Fri, 28 May 1999 16:53:52 +0600 (ESD) From: Max Gotlib <max@cca.usart.ru> To: Chuck Robey <chuckr@picnic.mat.net> Cc: hackers@FreeBSD.ORG Subject: Re: Serial ports programming Message-ID: <Pine.LNX.3.95.990528163613.6660C-100000@linux.cca.usart.ru> In-Reply-To: <Pine.BSF.4.10.9905271054580.375-100000@picnic.mat.net>
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On Thu, 27 May 1999, Chuck Robey wrote: > On Thu, 27 May 1999, Max Gotlib wrote: > > > Hi! > > > > Some days ago I've faced with the following problem: > > I need some kind of action (while coding user space > > program actively handling the serial port) to get > > sure all the bytes I've wrote to it are _transmitted_. > > The rate that characters drain from a UART is determined by the > currently active bit rate AND the absence of any change in the DTR and > CTS lines. You can sleep the time involved in transmitting the > characters. You can set up to be notified of any changes in the state > of the DTR and CTS lines, from the driver, and do that portably too > (signals). As long as you don't get a signal to indicate the change, > and you wait the time period it takes to drain the fifo, then you can > rely on the fact that the UART is drained. Hmmm... Digged into sio/tty* sources, I did not find a way to be woken up on CTS assertion... I know, I'm far from being called unix kernel guru. And a question: HOW ? Thanks in advance, Max. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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