From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 11/12] libata: use IRQ expecting Date: Mon, 21 Jun 2010 15:52:14 +0200 Message-ID: <4C1F6E8E.6050301@kernel.org> References: <1276443098-20653-1-git-send-email-tj@kernel.org> <1276443098-20653-12-git-send-email-tj@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:57383 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757674Ab0FUNww (ORCPT ); Mon, 21 Jun 2010 09:52:52 -0400 In-Reply-To: <1276443098-20653-12-git-send-email-tj@kernel.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: jeff@garzik.org Cc: mingo@elte.hu, tglx@linutronix.de, bphilips@suse.de, yinghai@kernel.org, akpm@linux-foundation.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, stern@rowland.harvard.edu, gregkh@suse.de, khali@linux-fr.org On 06/13/2010 05:31 PM, Tejun Heo wrote: > Thanks to its age, ATA is very susceptible to IRQ delivery problems in > both directions - lost and spurious interrupts. In traditional PATA, > the IRQ line is ultimately out of the controller and driver's control. > Even relatively new SATA isn't free from these issues. Many > controllers still emulate the traditional IDE interface which doesn't > have reliable way to indicate interrupt pending state and there also > is an issue regarding the interpretation of nIEN on both sides of the > cable. > > Most of these problems can be worked around by using the new IRQ > expecting mechanism without adding noticeable overhead. In ATA, > almost all operations are initiated by the host and the controller > signals progress or completion using IRQ. IRQ expecting can easily be > added in libata core and applied to all libata drivers. > > Signed-off-by: Tejun Heo Jeff, can you please ack this change if this looks okay to you? Also, would it okay to route this through irq tree? Thanks. -- tejun