From 566d1827df2ef0cbe921d3d6946ac3007b1a6938 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 15 Jan 2016 15:13:05 -0500 Subject: [PATCH] libata: disable forced PORTS_IMPL for >= AHCI 1.3 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 Cc: Sergei Shtylyov Cc: stable@vger.kernel.org --- 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 284a176076f5..402967902cbe 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 < AHCI 1.3 */ + if (!port_map && vers < 0x10300) { port_map = (1 << ahci_nr_ports(cap)) - 1; dev_warn(dev, "forcing PORTS_IMPL to 0x%x\n", port_map);