From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] libata: always use polling IDENTIFY Date: Sun, 03 Dec 2006 08:02:40 -0500 Message-ID: <4572CAF0.2040806@pobox.com> References: <20061203103032.GE11250@htj.dyndns.org> <20061203125603.493ebde6@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:15053 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1758466AbWLCNCn (ORCPT ); Sun, 3 Dec 2006 08:02:43 -0500 In-Reply-To: <20061203125603.493ebde6@localhost.localdomain> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cc: Tejun Heo , linux-ide@vger.kernel.org Alan wrote: > On Sun, 3 Dec 2006 19:30:32 +0900 > Tejun Heo wrote: > >> libata switched to IRQ-driven IDENTIFY when IRQ-driven PIO was >> introduced. This has caused a lot of problems including device >> misdetection and phantom device. >> >> ATA_FLAG_DETECT_POLLING was added recently to selectively use polling >> IDENTIFY on problemetic drivers but many controllers and devices are >> affected by this problem and trying to adding ATA_FLAG_DETECT_POLLING >> for each such case is diffcult and not very rewarding. >> >> This patch makes libata always use polling IDENTIFY. This is >> consistent with libata's original behavior and drivers/ide's behavior. >> >> Signed-off-by: Tejun Heo > > Acked-by: Alan Cox > > One possibility however would be to invert the flag we have now so we can > try turning -on- IRQ polling on some devices in future and maybe figure > it out that way around ? Agreed, though it is low priority. You'll note that Tejun's change only applies to the [large] set of drivers using libata-sff, rather than all drivers. Modern, unbridged SATA controllers (ahci, sata_sil24) continue to do their own interrupts based on received packets (FIS's) through the use of the higher level libata hooks. Jeff