Commit 566d1827 authored Jan 15, 2016 by Tejun Heo

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 <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>
Cc: stable@vger.kernel.org

parent b00622fc

drivers/ata/libahci.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);