From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: TASKFILE ioctl for libata? Date: Fri, 17 Feb 2006 03:38:22 -0500 Message-ID: <43F58B7E.4000401@pobox.com> References: <20060215143439.GA17850@harddisk-recovery.com> <43F37A5E.1090301@rtr.ca> <20060216005643.GA28396@harddisk-recovery.com> <43F3E17E.1090701@pobox.com> <43F4461C.1080501@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.dvmed.net ([216.237.124.58]:52177 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S964822AbWBQIia (ORCPT ); Fri, 17 Feb 2006 03:38:30 -0500 In-Reply-To: <43F4461C.1080501@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Erik Mouw , Mark Lord , linux-ide@vger.kernel.org Tejun Heo wrote: > Just a side note. Taskfile has finer granuality regarding which > registers are written and read back than current libata does and IDE > taskfile implementation is somewhat broken/weird in a few delicate fun > ways, so... be careful. Whoever tries it. Yes -- it opens the question about whether we care enough to fully support flagged taskfiles, and if not, how to best emulate that support under libata. I'm told that flagging individual ATA shadow registers for modification (or not) is required for issuing certain specialized PATA vendor-specific commands. SATA, OTOH, transmits all ATA shadow registers in a FIS, so flagged taskfiles are useless. So, I'm now thinking the best route is to leave the code as it is ;-) Rather than imperfectly implementing the flagged taskfile ioctl, punt the remaining userland users to SG_IO. I don't see lack of full flagged taskfile support as a big stumbling block to libata use. Jeff