From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757587AbYE2SOX (ORCPT ); Thu, 29 May 2008 14:14:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756702AbYE2SOG (ORCPT ); Thu, 29 May 2008 14:14:06 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:52853 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756549AbYE2SOB (ORCPT ); Thu, 29 May 2008 14:14:01 -0400 Message-ID: <483EF25F.7080005@garzik.org> Date: Thu, 29 May 2008 14:13:51 -0400 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Linus Torvalds CC: Alan Cox , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Subject: Re: RESEND: [PATCH] libata-sff: Fix oops reported in kerneloops.org for pnp devices with no ctl References: <20080529161453.24735.805.stgit@core> <483EEBE5.5030708@garzik.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.2.4 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > > On Thu, 29 May 2008, Jeff Garzik wrote: >>> It may be that you meant to make it an "else if" case, ie if there was no >>> IO-read, then you do a ndelay(400) as a last desperate case, but that's not >>> how your ata_sdd_sync() is actually written. >> The double-ndelay is definitely wrong, but we do need one. Technically it >> should -only- be a 400ns delay, but we also have a register read in there to >> make sure any posted writes are flushed. > > Well, but the "read + delay" is already in ata_sdd_pause(). Right, that's what I meant by double-ndelay. > So it's "ata_sdd_sync()" that I think is bogus. Based on its name alone, > it shouldn't have a delay in it (except, as mentioned, possibly for the > fallback case where no port can be used for reading). Agreed, Jeff