From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752761AbbBXCRN (ORCPT ); Mon, 23 Feb 2015 21:17:13 -0500 Received: from mail-pa0-f50.google.com ([209.85.220.50]:44617 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244AbbBXCRM (ORCPT ); Mon, 23 Feb 2015 21:17:12 -0500 Message-ID: <54EBDF22.3010804@gmail.com> Date: Tue, 24 Feb 2015 10:17:06 +0800 From: Peter Hung User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Johan Hovold CC: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, tom_tsai@fintek.com.tw, peter_hong@fintek.com.tw, Peter Hung Subject: Re: [PATCH V6 08/10] USB: f81232: fix read MSR strange value References: <1424073482-18164-1-git-send-email-hpeter+linux_kernel@gmail.com> <1424073482-18164-9-git-send-email-hpeter+linux_kernel@gmail.com> <20150217095136.GU2551@localhost> In-Reply-To: <20150217095136.GU2551@localhost> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Johan Hovold 於 2015/2/17 下午 05:51 寫道: >> So we add more check not only UART_MSR_ANY_DELTA but also with >> comparing DCD/RI/DSR/CTS change with old value. Due to the state >> bit is always correct, we direct save msr when read. >> >> The following step to reproduce this problem with while loop step 1~4: >> 1. ioctl(fd, TIOCMSET, &data) to set RTS or DTR >> 2. ioctl(fd, TIOCMGET, &data) to read CTS or DCD/DSR state >> 3. ioctl(fd, TIOCMSET, &data) to unset RTS or DTR >> 4. ioctl(fd, TIOCMGET, &data) to read CTS or DCD/DSR state > > Without having looked at this very closely; are you sure this is a > hardware issue and not related to the locking issues I pointed at in my > comments to tiocmset? > > Johan > Thank for your review. I'll apply all suggestions to next v7 patch. -- With Best Regards, Peter Hung