From mboxrd@z Thu Jan 1 00:00:00 1970 From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen) Subject: Re: Very strange data loss with jsm driver Date: Fri, 29 Jul 2011 14:06:50 -0400 Message-ID: <20110729180650.GL8562@caffeine.csclub.uwaterloo.ca> References: <20110729160416.GK8562@caffeine.csclub.uwaterloo.ca> <20110729172736.4b199d31@lxorguk.ukuu.org.uk> <20110729165342.GB8566@caffeine.csclub.uwaterloo.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caffeine.csclub.uwaterloo.ca ([129.97.134.17]:35098 "EHLO caffeine.csclub.uwaterloo.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752476Ab1G2SGu (ORCPT ); Fri, 29 Jul 2011 14:06:50 -0400 Content-Disposition: inline In-Reply-To: <20110729165342.GB8566@caffeine.csclub.uwaterloo.ca> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Lennart Sorensen Cc: Alan Cox , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Breno Leitao On Fri, Jul 29, 2011 at 12:53:42PM -0400, Lennart Sorensen wrote: > On Fri, Jul 29, 2011 at 05:27:36PM +0100, Alan Cox wrote: > > > The trigger point appears to be lines of up to 14 bytes, followed by > > > a newline. With 15 bytes or more per line it seems to be OK. > > > > > > Anyone got a clue? > > > > FIFO size perhaps - and some kind of missed wakeup or tx handling bug ? > > FIFO size is 64bytes, so that doesn't immediately sound related. > > The thing I find weird is that it thinks everything was sent right away. > > Also why should the newline have anything to do with it? If you send > 100100 bytes should it matter where the newlines are unless the tty > layer or the driver is interpreting the newlines for some reason. Same breakage on 2.6.18. I suspect this has always been broken. Hmm. I noticed fifosize in the uart_port info is set to 16, even though the fifo size is actually 64 bytes as all actual driver bits know. What is fifosize actually used for? -- Len Sorensen