From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932132AbcDDFTS (ORCPT ); Mon, 4 Apr 2016 01:19:18 -0400 Received: from mail.kernel.org ([198.145.29.136]:49860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753894AbcDDFQD (ORCPT ); Mon, 4 Apr 2016 01:16:03 -0400 Date: Mon, 4 Apr 2016 00:15:56 -0500 From: Rob Herring To: Srinivas Kandagatla Cc: Tejun Heo , linux-ide@vger.kernel.org, Andy Gross , Hans de Goede , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, jmaggard10@gmail.com Subject: Re: [PATCH v3 2/3] ata: ahci-platform: Add ports-implemented DT bindings. Message-ID: <20160404051556.GH17806@rob-hp-laptop> References: <1459497178-31090-1-git-send-email-srinivas.kandagatla@linaro.org> <1459497178-31090-3-git-send-email-srinivas.kandagatla@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459497178-31090-3-git-send-email-srinivas.kandagatla@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 01, 2016 at 08:52:57AM +0100, Srinivas Kandagatla wrote: > On some SOCs PORTS_IMPL register value is never programmed by the > firmware and left at zero value. Which means that no sata ports are > available for software. AHCI driver used to cope up with this by > fabricating the port_map if the PORTS_IMPL register is read zero, > but recent patch broke this workaround as zero value was valid for > NVMe disks. > > This patch adds ports-implemented DT bindings as workaround for this issue > in a way that DT can can override the PORTS_IMPL register in cases where > the firmware did not program it already. > > Fixes: 566d1827df2e ("libata: disable forced PORTS_IMPL for >= AHCI 1.3) > Signed-off-by: Srinivas Kandagatla > Acked-by: Tejun Heo > Reviewed-by: Andy Gross > --- > Documentation/devicetree/bindings/ata/ahci-platform.txt | 4 ++++ > drivers/ata/ahci_platform.c | 3 +++ > 2 files changed, 7 insertions(+) Acked-by: Rob Herring