From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 2.6.25-rc6] sata_promise: fix hardreset hotplug events, take 2 Date: Mon, 24 Mar 2008 11:19:32 +0900 Message-ID: <47E70FB4.4010802@gmail.com> References: <200803221421.m2MEL1oY021558@harpo.it.uu.se> <18406.38445.717175.664615@harpo.it.uu.se> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from wa-out-1112.google.com ([209.85.146.182]:49831 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754844AbYCXCTj (ORCPT ); Sun, 23 Mar 2008 22:19:39 -0400 Received: by wa-out-1112.google.com with SMTP id v27so3163114wah.23 for ; Sun, 23 Mar 2008 19:19:39 -0700 (PDT) In-Reply-To: <18406.38445.717175.664615@harpo.it.uu.se> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mikael Pettersson Cc: jeff@garzik.org, kurt@roeckx.be, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Mikael Pettersson wrote: > A Promise SATA controller will signal hotplug events when a hard > reset (COMRESET) is done on a port. These events aren't masked by > the driver, and the unexpected interrupts will cause a sequence > of failed reset attempts util libata's EH finally gives up. > > This has not been a common problem so far, but the pending libata > hardreset-by-default changes makes it a critical issue. > > The solution is to disable hotplug events before a reset, and to > reenable them afterwards. (Promise's driver does this too.) > > This patch adds SATA-specific versions of ->freeze() and ->thaw() > that also disable and enable hotplug events. PATA ports continue > to use the old versions of ->freeze() and ->thaw(). > > Accesses to the hotplug register must be serialised via host->lock. > We rely on ap->lock == &ap->host->lock and that libata takes this > lock before ->freeze() and ->thaw(). Document this requirement. > The interrupt handler is adjusted so its hotplug register accesses > are inside the region protected by host->lock. > > Tested on various chips (SATA300TX4, SATA300TX2plus, SATAII150TX4, > FastTrack TX4000) with various combinations of SATA and PATA disks, > with and without the pending hardreset-by-default changes. > > Signed-off-by: Mikael Pettersson Acked-by: Tejun Heo Jeff, do you want to merge this first? If so, I'll update the prefer-hardreset and cleanup-sht-ops patchsets; otherwise, I'll massage this patch a bit so that it fits on top of those two patchsets. -- tejun