From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: [RFC PATCH 2/2] ata: acpi: rework the ata acpi bind support Date: Thu, 15 Aug 2013 09:33:28 +0800 Message-ID: <520C2FE8.90009@intel.com> References: <1374731223-28685-1-git-send-email-aaron.lu@intel.com> <1374731223-28685-3-git-send-email-aaron.lu@intel.com> <20130725145229.GB26107@mtj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130725145229.GB26107@mtj.dyndns.org> Sender: linux-acpi-owner@vger.kernel.org To: Tejun Heo Cc: Aaron Lu , "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 List-Id: linux-ide@vger.kernel.org On 07/25/2013 10:52 PM, Tejun Heo wrote: > 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? Hi Tejun, This has been quiet for some time, may I know your opinion on this? Thanks, Aaron