From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: MSI broken in libata? Date: Mon, 11 Jan 2010 11:17:56 +0900 Message-ID: <4B4A8A54.8030406@kernel.org> References: <64bb37e0912250122n4e0e1842q88c0dad7e99ec6a7@mail.gmail.com> <4B484829.6060405@kernel.org> <64bb37e1001092033r1f0b4defw46c1a07101bb2d1b@mail.gmail.com> <4B4A7BC7.6060106@kernel.org> <4B4A815A.60503@gmail.com> 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]:43674 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751259Ab0AKCPx (ORCPT ); Sun, 10 Jan 2010 21:15:53 -0500 In-Reply-To: <4B4A815A.60503@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Robert Hancock Cc: Torsten Kaiser , linux-kernel@vger.kernel.org, Jeff Garzik , linux-ide@vger.kernel.org Hello, Robert. On 01/11/2010 10:39 AM, Robert Hancock wrote: > It'd be interesting to see if it makes a difference, but I don't think > the patch is quite right. According to the datasheet, doing the MSI ack > while the interrupt source is still pending will cause a new MSI to be > sent, so if you do it before handling the interrupt you'll generate a > spurious interrupt after every real one. Ah... okay, so the generation of MSI is level triggered? If so, your original patch is correct. I was thinking it might be edge triggered and it should be cleared before checking master event mask. Thanks. -- tejun