ata: Disable AHCI ALPM feature for Ampere Computing eMAG SATA

Due to hardware errata, Ampere Computing eMAG SATA can't support
AHCI ALPM feature. This patch disables the AHCI ALPM feature for
eMAG SATA.
Signed-off-by: Suman Trpathi <stripathi@amperecomputing.com>
Signed-off-by: Rameshwar Prasad Sahu <rameshwar.sahu@amperecomputing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/ata/ahci_platform.c

@@ -33,6 +33,13 @@ static const struct ata_port_info ahci_port_info = {
 	.port_ops	= &ahci_platform_ops,
 };
 
+static const struct ata_port_info ahci_port_info_nolpm = {
+	.flags		= AHCI_FLAG_COMMON | ATA_FLAG_NO_LPM,
+	.pio_mask	= ATA_PIO4,
+	.udma_mask	= ATA_UDMA6,
+	.port_ops	= &ahci_platform_ops,
+};
+
 static struct scsi_host_template ahci_platform_sht = {
 	AHCI_SHT(DRV_NAME),
 };
@@ -41,6 +48,7 @@ static int ahci_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct ahci_host_priv *hpriv;
+	const struct ata_port_info *port;
 	int rc;
 
 	hpriv = ahci_platform_get_resources(pdev,
@@ -58,7 +66,11 @@ static int ahci_probe(struct platform_device *pdev)
 	if (of_device_is_compatible(dev->of_node, "hisilicon,hisi-ahci"))
 		hpriv->flags |= AHCI_HFLAG_NO_FBS | AHCI_HFLAG_NO_NCQ;
 
-	rc = ahci_platform_init_host(pdev, hpriv, &ahci_port_info,
+	port = acpi_device_get_match_data(dev);
+	if (!port)
+		port = &ahci_port_info;
+
+	rc = ahci_platform_init_host(pdev, hpriv, port,
 				     &ahci_platform_sht);
 	if (rc)
 		goto disable_resources;
@@ -85,6 +97,7 @@ static const struct of_device_id ahci_of_match[] = {
 MODULE_DEVICE_TABLE(of, ahci_of_match);
 
 static const struct acpi_device_id ahci_acpi_match[] = {
+	{ "APMC0D33", (unsigned long)&ahci_port_info_nolpm },
 	{ ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) },
 	{},
 };