[PATCH 4/4] pata_platform: Use 16-bit wide data transfer

[Alexander Shiyan <shc_work@mail.ru>]

In some cases, system bus can be configured for 16-bit mode, in this
case using of read/write functions for the 32 bit values causes two
cycles of 16 bits, which is incorrect.
The patch provides its own function to use the proper 16-bit mode.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
---
 drivers/ata/pata_platform.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
index ecbc3bf..79dd223 100644
--- a/drivers/ata/pata_platform.c
+++ b/drivers/ata/pata_platform.c
@@ -43,13 +43,28 @@ static int pata_platform_set_mode(struct ata_link *link, struct ata_device **unu
 	return 0;
 }
 
+static unsigned int pata_platform_xfer_noirq(struct ata_device *dev,
+					     unsigned char *buf,
+					     unsigned int buflen, int rw)
+{
+	unsigned long flags;
+	unsigned int consumed;
+
+	local_irq_save(flags);
+	/* Use 16-bit transfer */
+	consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
+	local_irq_restore(flags);
+
+	return consumed;
+}
+
 static struct scsi_host_template pata_platform_sht = {
 	ATA_PIO_SHT(DRV_NAME),
 };
 
 static struct ata_port_operations pata_platform_port_ops = {
 	.inherits		= &ata_sff_port_ops,
-	.sff_data_xfer		= ata_sff_data_xfer_noirq,
+	.sff_data_xfer		= pata_platform_xfer_noirq,
 	.cable_detect		= ata_cable_unknown,
 	.set_mode		= pata_platform_set_mode,
 };
-- 
1.8.5.5