From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 3/5] libata: improve EH retry delay handling Date: Tue, 20 May 2008 13:02:22 +0900 Message-ID: <48324D4E.1040109@gmail.com> References: <12112174741373-git-send-email-htejun@gmail.com> <1211217475951-git-send-email-htejun@gmail.com> <20080519193311.01b5b928@core> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wf-out-1314.google.com ([209.85.200.172]:29506 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750700AbYETEC2 (ORCPT ); Tue, 20 May 2008 00:02:28 -0400 Received: by wf-out-1314.google.com with SMTP id 27so1604920wfd.4 for ; Mon, 19 May 2008 21:02:27 -0700 (PDT) In-Reply-To: <20080519193311.01b5b928@core> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: jeff@garzik.org, linux-ide@vger.kernel.org, liml@rtr.ca Alan Cox wrote: > On Tue, 20 May 2008 02:17:52 +0900 > Tejun Heo wrote: > >> EH retries were delayed by 5 seconds to ensure that resets don't occur >> back-to-back. However, this 5 second delay is superflous or excessive >> in many cases. For example, after IDENTIFY times out, there's no >> reason to wait five more seconds before retrying. > > You'll crash some ATAPI CD-ROM drives without that delay - at least for > PATA. As in power cycle required to get it back. > > Perhaps we should check cable type here ? No, no, the five secs is still there. e.g. Previously: reset (fail) - 5s retry wait - reset reset - IDENTIFY (30s timeout) - 5s retry wait - reset Now: reset (fail) - 5s retry wait - reset reset - IDENTIFY (30s timeout) - reset So, the inter-reset delay is never shorter than 5s. -- tejun