From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Polling (was Re: [PATCHSET 2/2] implement PMP support, take 6) Date: Tue, 02 Oct 2007 09:11:30 +0900 Message-ID: <47018CB2.8020008@gmail.com> References: <1190521193410-git-send-email-htejun@gmail.com> <46F9BF3E.5050708@garzik.org> <46FA1B4E.8090103@gmail.com> <46FD079F.3010007@garzik.org> <46FD0D50.8030602@gmail.com> <46FD1C4A.8010101@garzik.org> <46FD306C.3050205@gmail.com> <46FD5DE1.8000206@rtr.ca> <20070928220309.7c9ed816@the-village.bc.nu> <46FDADD9.9050007@garzik.org> <46FDE1A7.6030102@gmail.com> <4700F6BE.3060904@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from an-out-0708.google.com ([209.85.132.248]:55313 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752021AbXJBANM (ORCPT ); Mon, 1 Oct 2007 20:13:12 -0400 Received: by an-out-0708.google.com with SMTP id d31so582887and for ; Mon, 01 Oct 2007 17:13:11 -0700 (PDT) In-Reply-To: <4700F6BE.3060904@garzik.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: Alan Cox , Mark Lord , linux-ide@vger.kernel.org Jeff Garzik wrote: > Polling PMP 2.6.24 is completely unacceptable. It screws the 2.6.24 SAS > driver releases out of PMP. Not merging PMP has about the same effect for SAS, right? > I pulled your last PMP patchset, and will now endeavor to fix the API > prior to 2.6.24 merge window opening. I have a preliminary patch. The patch is pretty simple too. I'll submit after some testing but I'm not sure whether doing this right before the merge window is a good idea. I'd prefer not to support PMP on SAS for 2.6.24. > Linux high level message-submit / message-complete APIs should never > _require_ polling, even if its 100% polling under the hood. There are > far too many cases in the field where you don't have direct access to > hardware registers to poll. Or such polling would interfere with the > operation of other ports. Or any of a myriad of other reasons. I don't think that's true for actual ATA controllers but, for SAS, probably true. Is the frozen reset mechanism a headache too for SAS? Thanks. -- tejun