From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH] serial imx.c: fix CTS trigger level lower to avoid lost chars Date: Fri, 22 Jan 2010 11:07:01 +0000 Message-ID: <20100122110701.GA15699@shareable.org> References: <1264109163-28739-1-git-send-email-valentin.longchamp@epfl.ch> <20100121220653.GA21010@pengutronix.de> <20100121221133.GA30419@n2100.arm.linux.org.uk> <4B597A82.4020906@epfl.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail2.shareable.org ([80.68.89.115]:59507 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753497Ab0AVLHT (ORCPT ); Fri, 22 Jan 2010 06:07:19 -0500 Content-Disposition: inline In-Reply-To: <4B597A82.4020906@epfl.ch> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Valentin Longchamp Cc: Russell King - ARM Linux , "linux-arm-kernel@lists.infradead.org" , "s.hauer@pengutronix.de" , Wolfram Sang , "linux-serial@vger.kernel.org" Valentin Longchamp wrote: > First I wanted to fix the fact that the imx serial hardware only raises > the CTS pin when the oferflowing char begins to be set. I would have > solved this by setting the CTS trigger value to 31 instead of 32. But > when I talked with one colleague he told me about 16550A (that is > present nearly everywhere) that empty their TX FIFO, so I lowered it to 16. That seems quite peculiar because a 16550A only has a 16 byte receive buffer, doesn't it? And therefore it would have trouble talking reliably to another 16550A if it worked like that. I wonder what I'm not seeing in this picture. -- Jamie