From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 2/3] libata: Remove excess command issue delays Date: Fri, 14 May 2010 22:24:37 -0400 Message-ID: <4BEE05E5.70904@garzik.org> References: <20100505092350.586.46344.stgit@localhost.localdomain> <20100505092503.586.89942.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:37179 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751350Ab0EOCYk (ORCPT ); Fri, 14 May 2010 22:24:40 -0400 Received: by gyg13 with SMTP id 13so1368019gyg.19 for ; Fri, 14 May 2010 19:24:38 -0700 (PDT) In-Reply-To: <20100505092503.586.89942.stgit@localhost.localdomain> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: linux-ide@vger.kernel.org On 05/05/2010 05:25 AM, Alan Cox wrote: > /** > + * ata_sff_exec_command_nopost - issue ATA command to host controller > + * @ap: port to which command is being issued > + * @tf: ATA taskfile register set > + * > + * Issues ATA command, with proper synchronization with interrupt > + * handler / other threads. This version of the helper does not protect > + * against any delayed writes done by the underlying fabric, it must > + * therefore not be used for MMIO devices unless the device handles > + * the 400nS command delay stall internally. > + * > + * LOCKING: > + * spin_lock_irqsave(host lock) > + */ > +void ata_sff_exec_command_nopost(struct ata_port *ap, > + const struct ata_taskfile *tf) > +{ > + DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command); > + iowrite8(tf->command, ap->ioaddr.command_addr); > +} > +EXPORT_SYMBOL_GPL(ata_sff_exec_command_nopost); where did the 400ns delay go, for the 'nopost' version?