From: Tejun Heo <htejun@gmail.com>
To: Jeff Garzik <jeff@garzik.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, Mark Lord <liml@rtr.ca>,
linux-ide@vger.kernel.org
Subject: Re: Polling (was Re: [PATCHSET 2/2] implement PMP support, take 6)
Date: Tue, 02 Oct 2007 09:11:30 +0900 [thread overview]
Message-ID: <47018CB2.8020008@gmail.com> (raw)
In-Reply-To: <4700F6BE.3060904@garzik.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
next prev parent reply other threads:[~2007-10-02 0:13 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-23 4:19 [PATCHSET 2/2] implement PMP support, take 6 Tejun Heo
2007-09-23 4:19 ` [PATCH 01/10] libata-pmp: update ata_eh_reset() for PMP Tejun Heo
2007-09-23 4:19 ` [PATCH 03/10] libata-pmp: hook PMP support and enable it Tejun Heo
2007-09-23 4:19 ` [PATCH 04/10] libata-pmp: extend ACPI support to cover PMP Tejun Heo
2007-09-23 4:19 ` [PATCH 06/10] sata_sil24: implement PMP support Tejun Heo
2007-09-23 4:19 ` [PATCH 07/10] sata_sil24: implement PORT_RST Tejun Heo
2007-09-23 4:19 ` [PATCH 02/10] libata-pmp: implement Port Multiplier support Tejun Heo
2007-09-23 4:19 ` [PATCH 05/10] libata-pmp: implement qc_defer for command switching PMP support Tejun Heo
2007-09-23 4:19 ` [PATCH 08/10] ahci: implement " Tejun Heo
2007-09-23 4:19 ` [PATCH 09/10] ahci: move host flags over to pi.private_data Tejun Heo
2007-09-23 4:19 ` [PATCH 10/10] ahci: implement AHCI_HFLAG_NO_PMP Tejun Heo
2007-09-26 2:09 ` Polling (was Re: [PATCHSET 2/2] implement PMP support, take 6) Jeff Garzik
2007-09-26 2:12 ` Jeff Garzik
2007-09-26 8:41 ` Tejun Heo
2007-09-28 12:10 ` Tejun Heo
2007-09-28 13:54 ` Jeff Garzik
2007-09-28 14:18 ` Tejun Heo
2007-09-28 14:57 ` Alan Cox
2007-09-28 15:20 ` Jeff Garzik
2007-09-28 15:43 ` Alan Cox
2007-09-28 15:40 ` Jeff Garzik
2007-09-28 20:00 ` Mark Lord
2007-09-29 1:49 ` Jeff Garzik
2007-09-29 3:29 ` Jeff Garzik
2007-09-29 4:58 ` Andrew Morton
2007-09-29 5:09 ` Jeff Garzik
2007-09-29 16:51 ` Greg Freemyer
2007-09-29 20:56 ` Alan Cox
2007-10-01 12:28 ` Jeff Garzik
2007-09-28 15:22 ` Jeff Garzik
2007-09-28 16:48 ` Tejun Heo
2007-09-28 20:02 ` Mark Lord
2007-09-28 20:25 ` Bartlomiej Zolnierkiewicz
2007-09-28 21:03 ` Alan Cox
2007-09-29 1:43 ` Jeff Garzik
2007-09-29 5:24 ` Tejun Heo
2007-10-01 13:31 ` Jeff Garzik
2007-10-02 0:11 ` Tejun Heo [this message]
2007-10-02 14:25 ` Alan Cox
2007-10-02 14:30 ` Jeff Garzik
2007-09-29 12:32 ` Mark Lord
2007-10-01 12:38 ` Jeff Garzik
2007-10-02 0:12 ` Tejun Heo
2007-10-02 12:56 ` Jeff Garzik
2007-10-02 13:06 ` Mark Lord
2007-10-02 13:30 ` Jeff Garzik
2007-10-06 22:02 ` Tejun Heo
2007-10-09 2:09 ` Jeff Garzik
2007-10-09 6:54 ` Tejun Heo
2007-09-28 14:20 ` Mark Lord
2007-09-28 15:36 ` Jeff Garzik
2007-09-28 15:55 ` Alan Cox
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