[PATCH 4.14 17/31] ata: pata_hpt37x: disable primary channel on HPT371

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Sergey Shtylyov <s.shtylyov@omp.ru>

commit 8d093e02e898b24c58788b0289e3202317a96d2a upstream.

The HPT371 chip physically has only one channel, the secondary one,
however the primary channel registers do exist! Thus we have to
manually disable the non-existing channel if the BIOS hasn't done this
already. Similarly to the pata_hpt3x2n driver, always disable the
primary channel.

Fixes: 669a5db411d8 ("[libata] Add a bunch of PATA drivers.")
Cc: stable@vger.kernel.org
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/ata/pata_hpt37x.c |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

--- a/drivers/ata/pata_hpt37x.c
+++ b/drivers/ata/pata_hpt37x.c
@@ -920,6 +920,20 @@ static int hpt37x_init_one(struct pci_de
 	pci_write_config_byte(dev, 0x5a, irqmask);
 
 	/*
+	 * HPT371 chips physically have only one channel, the secondary one,
+	 * but the primary channel registers do exist!  Go figure...
+	 * So,  we manually disable the non-existing channel here
+	 * (if the BIOS hasn't done this already).
+	 */
+	if (dev->device == PCI_DEVICE_ID_TTI_HPT371) {
+		u8 mcr1;
+
+		pci_read_config_byte(dev, 0x50, &mcr1);
+		mcr1 &= ~0x04;
+		pci_write_config_byte(dev, 0x50, mcr1);
+	}
+
+	/*
 	 * default to pci clock. make sure MA15/16 are set to output
 	 * to prevent drives having problems with 40-pin cables. Needed
 	 * for some drives such as IBM-DTLA which will not enter ready