Without the patch the kernel generates the following error.

 ata11.15: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
 ata11.15: Port Multiplier vendor mismatch '0x197b' != '0x123'
 ata11.15: PMP revalidation failed (errno=-19)
 ata11.15: failed to recover PMP after 5 tries, giving up

This patch helps to bypass this error and the device becomes
functional.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: <linux-ide@vger.kernel.org>
Cc: stable@vger.kernel.org