ata: ahci: append new hflag AHCI_HFLAG_NO_FBS

Append AHCI_HFLAG_NO_FBS to force turning off FBS flag.
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Kefeng Wang <kefeng.wang@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/ahci.h

@@ -235,6 +235,7 @@ enum {
 						        port start (wait until
 						        error-handling stage) */
 	AHCI_HFLAG_MULTI_MSI		= (1 << 16), /* multiple PCI MSIs */
+	AHCI_HFLAG_NO_FBS		= (1 << 17), /* no FBS */
 
 	/* ap->flags bits */
 

drivers/ata/libahci.c

@@ -457,6 +457,11 @@ void ahci_save_initial_config(struct device *dev,
 		cap |= HOST_CAP_FBS;
 	}
 
+	if ((cap & HOST_CAP_FBS) && (hpriv->flags & AHCI_HFLAG_NO_FBS)) {
+		dev_info(dev, "controller can't do FBS, turning off CAP_FBS\n");
+		cap &= ~HOST_CAP_FBS;
+	}
+
 	if (force_port_map && port_map != force_port_map) {
 		dev_info(dev, "forcing port_map 0x%x -> 0x%x\n",
 			 port_map, force_port_map);