[PATCH v3] ata: Disable AHCI ALPM feature for Ampere Computing eMAG SATA

[stripathi@amperecomputing.com (Suman Tripathi)]

Due to hardware errata, Ampere Computing eMAG SATA can't support
AHCI ALPM feature. This patch disables the AHCI ALPM feature for
eMAG SATA.

Changes for v2:

* Introduce the new ata_port_info object which includes ATA_FLAG_NO_LPM.
* Include this object for eMAG SATA inside the acpi match table.
* Retrieve the ata_port_info from the acpi match table.

Changes for v3:

* Fix the indentation and whitespace warnings.

Signed-off-by: Suman Trpathi <stripathi@amperecomputing.com>
Signed-off-by: Rameshwar Prasad Sahu <rameshwar.sahu@amperecomputing.com>
---
 drivers/ata/ahci_platform.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 99f9a89..9ba283f 100644
--- a/drivers/ata/ahci_platform.c
+++ b/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);
@@ -57,7 +65,11 @@ 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) },
        {},
 };
--
2.7.4

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