[PATCH] ata: ahci: Lookup PCS register offset based on PCI device ID

From: Stephen Douthit
Date: Thu Aug 08 2019 - 16:24:39 EST


Intel moved the PCS register from 0x92 to 0x94 on Denverton for some
reason, so now we get to check the device ID before poking it on reset.

Signed-off-by: Stephen Douthit <stephend@xxxxxxxxxxxxxxx>
---
drivers/ata/ahci.c | 42 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index f7652baa6337..7090c7754fc2 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -623,6 +623,41 @@ static void ahci_pci_save_initial_config(struct pci_dev *pdev,
ahci_save_initial_config(&pdev->dev, hpriv);
}

+/*
+ * Intel moved the PCS register on the Denverton AHCI controller, see which
+ * offset this controller is using
+ */
+static int ahci_pcs_offset(struct ata_host *host)
+{
+ struct pci_dev *pdev = to_pci_dev(host->dev);
+
+ switch (pdev->device) {
+ case 0x19b0:
+ case 0x19b1:
+ case 0x19b2:
+ case 0x19b3:
+ case 0x19b4:
+ case 0x19b5:
+ case 0x19b6:
+ case 0x19b7:
+ case 0x19bE:
+ case 0x19bF:
+ case 0x19c0:
+ case 0x19c1:
+ case 0x19c2:
+ case 0x19c3:
+ case 0x19c4:
+ case 0x19c5:
+ case 0x19c6:
+ case 0x19c7:
+ case 0x19cE:
+ case 0x19cF:
+ return 0x94;
+ }
+
+ return 0x92;
+}
+
static int ahci_pci_reset_controller(struct ata_host *host)
{
struct pci_dev *pdev = to_pci_dev(host->dev);
@@ -634,13 +669,14 @@ static int ahci_pci_reset_controller(struct ata_host *host)

if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
struct ahci_host_priv *hpriv = host->private_data;
+ int pcs = ahci_pcs_offset(host);
u16 tmp16;

/* configure PCS */
- pci_read_config_word(pdev, 0x92, &tmp16);
+ pci_read_config_word(pdev, pcs, &tmp16);
if ((tmp16 & hpriv->port_map) != hpriv->port_map) {
- tmp16 |= hpriv->port_map;
- pci_write_config_word(pdev, 0x92, tmp16);
+ tmp16 |= hpriv->port_map & 0xff;
+ pci_write_config_word(pdev, pcs, tmp16);
}
}

--
2.21.0