From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH] libata: disable forced PORTS_IMPL for >= v3.0 controllers Date: Thu, 14 Jan 2016 17:37:32 -0500 Message-ID: <20160114223732.GG3520@mtj.duckdns.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-yk0-f170.google.com ([209.85.160.170]:36753 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751621AbcANWhe (ORCPT ); Thu, 14 Jan 2016 17:37:34 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Andy Lutomirski Cc: linux-ide@vger.kernel.org, "linux-kernel@vger.kernel.org" Some early controllers incorrectly reported zero ports in PORTS_IMPL register and the ahci driver fabricates PORTS_IMPL from the number of ports in those cases. This hasn't mattered but with the new nvme controllers there are cases where zero PORTS_IMPL is valid and should be honored. Disable the workaround for controllers >= v3.0. Signed-off-by: Tejun Heo Reported-by: Andy Lutomirski Link: http://lkml.kernel.org/g/CALCETrU7yMvXEDhjAUShoHEhDwifJGapdw--BKxsP0jmjKGmRw@mail.gmail.com --- Hello, Andy. Can you please test whether this fixes the issue? Thanks. drivers/ata/libahci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index d61740e..4931075 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -496,8 +496,8 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv) } } - /* fabricate port_map from cap.nr_ports */ - if (!port_map) { + /* fabricate port_map from cap.nr_ports for older controllers */ + if (!port_map && (vers >> 16) <= 2) { port_map = (1 << ahci_nr_ports(cap)) - 1; dev_warn(dev, "forcing PORTS_IMPL to 0x%x\n", port_map);