libata: update ->data_xfer hook for ATAPI
Depending on how many bytes are transferred as a unit, PIO data
transfer may consume more bytes than requested. Knowing how much
data is consumed is necessary to determine how much is left for
draining. This patch update ->data_xfer such that it returns the
number of consumed bytes.
While at it, it also makes the following changes.
* s/adev/dev/
* use READ/WRITE constants for rw indication
* misc clean ups
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/pata_legacy.c b/drivers/ata/pata_legacy.c
index 17159b5..dae85aa 100644
--- a/drivers/ata/pata_legacy.c
+++ b/drivers/ata/pata_legacy.c
@@ -249,13 +249,14 @@
}
-static void pdc_data_xfer_vlb(struct ata_device *adev, unsigned char *buf, unsigned int buflen, int write_data)
+static unsigned int pdc_data_xfer_vlb(struct ata_device *dev,
+ unsigned char *buf, unsigned int buflen, int rw)
{
- struct ata_port *ap = adev->link->ap;
- int slop = buflen & 3;
- unsigned long flags;
-
if (ata_id_has_dword_io(adev->id)) {
+ struct ata_port *ap = dev->link->ap;
+ int slop = buflen & 3;
+ unsigned long flags;
+
local_irq_save(flags);
/* Perform the 32bit I/O synchronization sequence */
@@ -264,26 +265,27 @@
ioread8(ap->ioaddr.nsect_addr);
/* Now the data */
-
- if (write_data)
- iowrite32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);
- else
+ if (rw == READ)
ioread32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);
+ else
+ iowrite32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);
if (unlikely(slop)) {
- __le32 pad = 0;
- if (write_data) {
- memcpy(&pad, buf + buflen - slop, slop);
- iowrite32(le32_to_cpu(pad), ap->ioaddr.data_addr);
- } else {
+ u32 pad;
+ if (rw == READ) {
pad = cpu_to_le32(ioread32(ap->ioaddr.data_addr));
memcpy(buf + buflen - slop, &pad, slop);
+ } else {
+ memcpy(&pad, buf + buflen - slop, slop);
+ iowrite32(le32_to_cpu(pad), ap->ioaddr.data_addr);
}
+ buflen += 4 - slop;
}
local_irq_restore(flags);
- }
- else
- ata_data_xfer_noirq(adev, buf, buflen, write_data);
+ } else
+ buflen = ata_data_xfer_noirq(dev, buf, buflen, rw);
+
+ return buflen;
}
static struct ata_port_operations pdc20230_port_ops = {