From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 1/2] ahci: preserve PORTS_IMPL over host resets Date: Thu, 05 Oct 2006 07:27:05 -0400 Message-ID: <4524EC09.2070608@pobox.com> References: <20060930122121.GR25800@htj.dyndns.org> 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]:25054 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1750768AbWJEL1H (ORCPT ); Thu, 5 Oct 2006 07:27:07 -0400 In-Reply-To: <20060930122121.GR25800@htj.dyndns.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: linux-ide@vger.kernel.org, robbat2@gentoo.org Tejun Heo wrote: > Instead of writing 0xf blindly, preserve the content of write-once > PORTS_IMPL register over host resets. > > This patch is taken from Jeff Garzik's AHCI init update patch. > > Signed-off-by: Tejun Heo > Cc: Jeff Garzik One reason why I didn't go ahead and apply this is for uninitalized-by-BIOS cases that are the reason I originally hardcoded a 0xf value into the register. This patch is OK, iff we also include a test to see if impl_save==0 prior to global reset. If that is the case, we should hardcode 0xf or (1<