From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755366AbaIQK2V (ORCPT ); Wed, 17 Sep 2014 06:28:21 -0400 Received: from filter1.ibarracuda.nl ([83.247.7.10]:56083 "EHLO filter1.ibarracuda.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754558AbaIQK2R (ORCPT ); Wed, 17 Sep 2014 06:28:17 -0400 X-ASG-Debug-ID: 1410949694-0759e7612910bb80002-xx1T2L X-Barracuda-Envelope-From: Frans.Klaver@xsens.com X-Barracuda-AUTH-User: xsenscom X-Barracuda-Apparent-Source-IP: 87.249.116.215 Date: Wed, 17 Sep 2014 12:28:12 +0200 From: Frans Klaver To: Sebastian Andrzej Siewior CC: Heikki Krogerus , Peter Hurley , , , , , , , , Alan Cox Subject: Re: [PATCH 09/16] tty: serial: 8250_dma: Add a TX trigger workaround for AM33xx Message-ID: <20140917102812.GA20438@ci00147.xsens-tech.local> X-ASG-Orig-Subj: Re: [PATCH 09/16] tty: serial: 8250_dma: Add a TX trigger workaround for AM33xx References: <5411967A.6090406@hurleysoftware.com> <54119AAA.9080907@linutronix.de> <20140911151114.GD28458@ci00147.xsens-tech.local> <5411C810.7070906@linutronix.de> <2cf997d9-e7de-465b-915d-3a0a5e7b95f7@email.android.com> <54129F6C.7040508@linutronix.de> <20140912094010.GE28458@ci00147.xsens-tech.local> <5412C21A.8020203@linutronix.de> <20140912102816.GF28458@ci00147.xsens-tech.local> <541716DC.9020904@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <541716DC.9020904@linutronix.de> User-Agent: Mutt/1.5.23 (2014-03-12) X-Originating-IP: [172.16.11.160] X-Barracuda-Connect: rev-215.116.249.87.virtu.nl[87.249.116.215] X-Barracuda-Start-Time: 1410949694 X-Barracuda-Encrypted: AES128-SHA X-Barracuda-URL: http://filter1.ibarracuda.nl:8000/cgi-mod/mark.cgi X-Barracuda-BRTS-Status: 1 X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=5.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.3.9577 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Yesterday's testing was a bit messy. So here goes again. On Mon, Sep 15, 2014 at 06:42:04PM +0200, Sebastian Andrzej Siewior wrote: > On 09/12/2014 12:28 PM, Frans Klaver wrote: > > port config is 115200 8N1. I don't recall doing anything special. I > > boot, login, less file and get a lock. > > So I booted my mini Debian 7.6 (basic system + openssh) on my beagle > bone black which is: > > [ 0.000000] AM335X ES2.0 (neon ) Mine's the same. > configured a console, login, invoked "less file". The file was shown, I > hit on the space key so less shows me more of the file. No lock-up. > I tried booting via NFS and MMC. I tried various files with less. > > My dot config is here > https://breakpoint.cc/config-am335x-bb.txt.xz > > If there is nothing specific to the file you do less on I have no idea > what else it could if it is not the config. It could be environmental. I have three test cases right now. Two of them on the beagle bone black, the third on our custom am335x based platform. - All test cases run the same kernel built from uart_v10-pre1. - For the black, the board, dtb, and u-boot environment are equal for the test cases. - Bone Black: Debian 7.5 Login, "less file" doesn't lock up. Scrolling down looks sensible. Scrolling up leaves me with a crooked display, provided the minicom window is more than 24 lines high. Condensed example: Normal less looks like: Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in : While after scrolling up it looks like minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in : Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad vi works sensibly, but only occupies part of the total screen estate in minicom. After quitting, minicom doesn't use the rest of the screen estate anymore. After running vi, less doesn't show the weird scrolling behavior anymore, since the console has just been limited to 24x80. - Bone Black: Yocto poky, core-image-minimal Login, "less file" locks up, doesn't show anything. I can exit using Ctrl-C. vi runs normally, only occupies part of the total screen estate in minicom. After quitting, a weird character shows up (typically I see ÿ there), but minicom can use the rest of the screen estate again. If we disregard the odd character, this is much like the behavior we have on the omap-serial driver. - Custom board: Yocto poky, custom image Login, "less file" locks up, showing only "ÿ" in the top left corner of the screen. Can get out of there by having something dumped through /dev/kmsg. vi: see "Bone Black: Yocto poky, core-image-minimal" Having it summed up like this, I think we're back at ncurses and its interaction with the serial driver. Hope this helps. Thanks for your effort so far, Frans