From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Date: Fri, 23 Mar 2018 16:51:16 +0100 Subject: [PATCH 0/5] serial: implement flow control for ASPEED VUART driver In-Reply-To: <20180321025241.19785-1-jk@ozlabs.org> References: <20180321025241.19785-1-jk@ozlabs.org> Message-ID: <20180323155116.GA31423@kroah.com> List-Id: To: linux-aspeed@lists.ozlabs.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed, Mar 21, 2018 at 10:52:36AM +0800, Jeremy Kerr wrote: > This series implements flow control for the ASPEED VUART driver. This > hardware is slightly unusual in that the RX data rate can quickly > overwhelm the flip buffer code, so the ldisc-driven throttle/unthrottle > mechanisms don't entirely solve the problem. > > To do this, we have a couple of minor changes to the tty core, as well > as an update to the tty proc interface to display buffer overrun metrics > (entirely optional, but does allow us to see the problem). > > Then, we implement the standard throttle mechanism, and augment it with > a fast-path to throttle if we overrun the flip buffers before the ldisc > has had a chance to run. > > Questions and comments most welcome; I'm fairly new to the tty layer. I've applied patch 2 here, can you redo the series again after fixing up the first one and include the v2 of patch 5 so it's easier for me to figure out what to really apply here? thanks, greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linuxfoundation.org (client-ip=140.211.169.12; helo=mail.linuxfoundation.org; envelope-from=gregkh@linuxfoundation.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4077Lc11FWzF1HC; Sat, 24 Mar 2018 02:51:20 +1100 (AEDT) Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 02FF61073; Fri, 23 Mar 2018 15:51:17 +0000 (UTC) Date: Fri, 23 Mar 2018 16:51:16 +0100 From: Greg Kroah-Hartman To: Jeremy Kerr Cc: linux-serial@vger.kernel.org, linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org, Joel Stanley , Andrew Jeffery , Jiri Slaby Subject: Re: [PATCH 0/5] serial: implement flow control for ASPEED VUART driver Message-ID: <20180323155116.GA31423@kroah.com> References: <20180321025241.19785-1-jk@ozlabs.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180321025241.19785-1-jk@ozlabs.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Mar 2018 15:51:20 -0000 On Wed, Mar 21, 2018 at 10:52:36AM +0800, Jeremy Kerr wrote: > This series implements flow control for the ASPEED VUART driver. This > hardware is slightly unusual in that the RX data rate can quickly > overwhelm the flip buffer code, so the ldisc-driven throttle/unthrottle > mechanisms don't entirely solve the problem. > > To do this, we have a couple of minor changes to the tty core, as well > as an update to the tty proc interface to display buffer overrun metrics > (entirely optional, but does allow us to see the problem). > > Then, we implement the standard throttle mechanism, and augment it with > a fast-path to throttle if we overrun the flip buffers before the ldisc > has had a chance to run. > > Questions and comments most welcome; I'm fairly new to the tty layer. I've applied patch 2 here, can you redo the series again after fixing up the first one and include the v2 of patch 5 so it's easier for me to figure out what to really apply here? thanks, greg k-h