From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [RFC PATCH 2/2] ata: acpi: rework the ata acpi bind support Date: Thu, 25 Jul 2013 10:52:29 -0400 Message-ID: <20130725145229.GB26107@mtj.dyndns.org> References: <1374731223-28685-1-git-send-email-aaron.lu@intel.com> <1374731223-28685-3-git-send-email-aaron.lu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-gh0-f175.google.com ([209.85.160.175]:57902 "EHLO mail-gh0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756417Ab3GYOwf (ORCPT ); Thu, 25 Jul 2013 10:52:35 -0400 Content-Disposition: inline In-Reply-To: <1374731223-28685-3-git-send-email-aaron.lu@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Aaron Lu Cc: "Rafael J. Wysocki" , James Bottomley , Jeff Wu , Shane Huang , Matthew Garrett , Holger Macht , Zhang Rui , linux-ide@vger.kernel.org, linux-acpi@vger.kernel.org, linux-scsi@vger.kernel.org On Thu, Jul 25, 2013 at 01:47:03PM +0800, Aaron Lu wrote: > Binding ACPI handle to SCSI device has several drawbacks, namely: > 1 During ATA device initialization time, ACPI handle will be needed > while SCSI devices are not created yet. So each time ACPI handle is > needed, instead of retrieving the handle by ACPI_HANDLE macro, > a namespace scan is performed to find the handle for the corresponding > ATA device. This is inefficient, and also expose a restriction on > calling path not holding any lock. > 2 The binding to SCSI device tree makes code complex, while at the same > time doesn't bring us any benefit. All ACPI handlings are still done > in ATA module, not in SCSI. > > Rework the ATA ACPI binding code to bind ACPI handle to ATA transport > devices(ATA port and ATA device). The binding needs to be done only once, > since the ATA transport devices do not go away with hotplug. And due to > this, the flush_work call in hotplug handler for ATA bay is no longer > needed. I like it but am wondering why we weren't doing this before. Was the acpi support added before we made ata objects proper devices? Thanks. -- tejun