From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: RESEND: [PATCH] libata-sff: Fix oops reported in kerneloops.org for pnp devices with no ctl Date: Thu, 29 May 2008 11:04:08 -0700 (PDT) Message-ID: References: <20080529161453.24735.805.stgit@core> <483EEBE5.5030708@garzik.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:44182 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752498AbYE2SEV (ORCPT ); Thu, 29 May 2008 14:04:21 -0400 In-Reply-To: <483EEBE5.5030708@garzik.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: Alan Cox , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org 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(). 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). Linus