From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] libata: sata_down_spd_limit should return if driver has not recorded sstatus speed Date: Mon, 4 Dec 2017 13:57:36 -0800 Message-ID: <20171204215736.GO2421075@devbig577.frc2.facebook.com> References: <1510697845-58071-1-git-send-email-dmilburn@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-qt0-f195.google.com ([209.85.216.195]:38179 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752605AbdLDV5j (ORCPT ); Mon, 4 Dec 2017 16:57:39 -0500 Received: by mail-qt0-f195.google.com with SMTP id d4so24635347qtj.5 for ; Mon, 04 Dec 2017 13:57:39 -0800 (PST) Content-Disposition: inline In-Reply-To: <1510697845-58071-1-git-send-email-dmilburn@redhat.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: David Milburn Cc: linux-ide@vger.kernel.org On Tue, Nov 14, 2017 at 04:17:25PM -0600, David Milburn wrote: > During hotplug, it is possible for 6Gbps link speed to > be limited all the way down to 1.5 Gbps which may lead > to a slower link speed when drive is re-connected. > > This behavior has been seen on a Intel Lewisburg SATA > controller (8086:a1d2) with HGST HUH728080ALE600 drive > where SATA link speed was limited to 1.5 Gbps and > when re-connected the link came up 3.0 Gbps. > > This patch was retested on above configuration and > showed the hotplugged link to come back online at max > speed (6Gbps). I did not see the downgrade when testing > on Intel C600/X79, but retested patched linux-4.14-rc5 > kernel and didn't see any side effects from this > change. Also, successfully retested hotplug on port > multiplier 3Gbps link. > > Signed-off-by: David Milburn Applied to libata/for-4.15-fixes. Thanks. -- tejun