From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH v2] libata: disable forced PORTS_IMPL for >= AHCI 1.3 Date: Fri, 15 Jan 2016 15:13:05 -0500 Message-ID: <20160115201305.GN3520@mtj.duckdns.org> References: <20160114223732.GG3520@mtj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20160114223732.GG3520@mtj.duckdns.org> Sender: linux-kernel-owner@vger.kernel.org To: Andy Lutomirski Cc: linux-ide@vger.kernel.org, "linux-kernel@vger.kernel.org" List-Id: linux-ide@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 >= AHCI 1.3. 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 see whether this one works? Thanks. drivers/ata/libahci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index d61740e..a91432a 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -496,8 +496,9 @@ 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 < AHCI 1.3 */ + if (!port_map && (!(vers >> 16) || + ((vers >> 16) == 1 && (vers & 0xFFFF) < 0x300))) { port_map = (1 << ahci_nr_ports(cap)) - 1; dev_warn(dev, "forcing PORTS_IMPL to 0x%x\n", port_map);