libata: disable forced PORTS_IMPL for >= AHCI 1.3

commit 566d1827df2ef0cbe921d3d6946ac3007b1a6938 upstream.

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 <tj@kernel.org>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/g/CALCETrU7yMvXEDhjAUShoHEhDwifJGapdw--BKxsP0jmjKGmRw@mail.gmail.com
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wt: file is drivers/ata/ahci.c in 2.6.32]
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 6787aab9a26500868e8efd4beb00f537e6207080..c075664a8161fc7d8c132f3cb5d4b959f6a82dff 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -924,8 +924,8 @@ static void ahci_save_initial_config(struct pci_dev *pdev,
                }
        }
 
-       /* 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_printk(KERN_WARNING, &pdev->dev,
                           "forcing PORTS_IMPL to 0x%x\n", port_map);