* [PATCH 1/2] libata ata_data_xfer() fix
2005-08-12 6:09 [PATCH 0/2] libata PIO fixes (revised) Albert Lee
@ 2005-08-12 6:15 ` Albert Lee
2005-08-12 6:17 ` [PATCH 2/2] libata handle the case when device returns/needs extra data Albert Lee
2005-08-12 6:45 ` [PATCH 0/2] libata PIO fixes (revised) Jeff Garzik
2 siblings, 0 replies; 4+ messages in thread
From: Albert Lee @ 2005-08-12 6:15 UTC (permalink / raw)
To: Jeff Garzik; +Cc: IDE Linux, Bartlomiej Zolnierkiewicz, Doug Maxey
[-- Attachment #1: Type: text/plain, Size: 354 bytes --]
Jeff,
PATCH 1/2: ata_data_xfer() fix
Changes:
- Modify ata_mmio_data_xfer() and ata_pio_data_xfer() to handle odd-lengthed buffer.
- Add some function comments
This patch does not reuse ap->pad as alignment buffer since
using local variable seems good enough.
For your review, thanks.
Albert
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
[-- Attachment #2: pio1.diff --]
[-- Type: text/plain, Size: 3957 bytes --]
--- linux/drivers/scsi/libata-core.c 2005-08-12 10:31:52.000000000 +0800
+++ 01_align/drivers/scsi/libata-core.c 2005-08-12 11:14:45.000000000 +0800
@@ -2519,6 +2519,20 @@
#endif /* __BIG_ENDIAN */
}
+/**
+ * ata_mmio_data_xfer - Transfer data by MMIO
+ * @ap: port to read/write
+ * @buf: data buffer
+ * @buflen: buffer length
+ * @do_write: read/write
+ *
+ * Transfer data from/to the device data register by MMIO.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ *
+ */
+
static void ata_mmio_data_xfer(struct ata_port *ap, unsigned char *buf,
unsigned int buflen, int write_data)
{
@@ -2527,6 +2541,7 @@
u16 *buf16 = (u16 *) buf;
void __iomem *mmio = (void __iomem *)ap->ioaddr.data_addr;
+ /* Transfer multiple of 2 bytes */
if (write_data) {
for (i = 0; i < words; i++)
writew(le16_to_cpu(buf16[i]), mmio);
@@ -2534,19 +2549,76 @@
for (i = 0; i < words; i++)
buf16[i] = cpu_to_le16(readw(mmio));
}
+
+ /* Transfer trailing 1 byte, if any. */
+ if (unlikely(buflen & 0x01)) {
+ u16 align_buf[1] = { 0 };
+ unsigned char *trailing_buf = buf + buflen - 1;
+
+ if (write_data) {
+ memcpy(align_buf, trailing_buf, 1);
+ writew(le16_to_cpu(align_buf[0]), mmio);
+ } else {
+ align_buf[0] = cpu_to_le16(readw(mmio));
+ memcpy(trailing_buf, align_buf, 1);
+ }
+ }
}
+/**
+ * ata_pio_data_xfer - Transfer data by PIO
+ * @ap: port to read/write
+ * @buf: data buffer
+ * @buflen: buffer length
+ * @do_write: read/write
+ *
+ * Transfer data from/to the device data register by PIO.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ *
+ */
+
static void ata_pio_data_xfer(struct ata_port *ap, unsigned char *buf,
unsigned int buflen, int write_data)
{
- unsigned int dwords = buflen >> 1;
+ unsigned int words = buflen >> 1;
+ /* Transfer multiple of 2 bytes */
if (write_data)
- outsw(ap->ioaddr.data_addr, buf, dwords);
+ outsw(ap->ioaddr.data_addr, buf, words);
else
- insw(ap->ioaddr.data_addr, buf, dwords);
+ insw(ap->ioaddr.data_addr, buf, words);
+
+ /* Transfer trailing 1 byte, if any. */
+ if (unlikely(buflen & 0x01)) {
+ u16 align_buf[1] = { 0 };
+ unsigned char *trailing_buf = buf + buflen - 1;
+
+ if (write_data) {
+ memcpy(align_buf, trailing_buf, 1);
+ outw(le16_to_cpu(align_buf[0]), ap->ioaddr.data_addr);
+ } else {
+ align_buf[0] = cpu_to_le16(inw(ap->ioaddr.data_addr));
+ memcpy(trailing_buf, align_buf, 1);
+ }
+ }
}
+/**
+ * ata_data_xfer - Transfer data from/to the data register.
+ * @ap: port to read/write
+ * @buf: data buffer
+ * @buflen: buffer length
+ * @do_write: read/write
+ *
+ * Transfer data from/to the device data register.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ *
+ */
+
static void ata_data_xfer(struct ata_port *ap, unsigned char *buf,
unsigned int buflen, int do_write)
{
@@ -2556,6 +2628,16 @@
ata_pio_data_xfer(ap, buf, buflen, do_write);
}
+/**
+ * ata_pio_sector - Transfer ATA_SECT_SIZE (512 bytes) of data.
+ * @qc: Command on going
+ *
+ * Transfer ATA_SECT_SIZE of data from/to the ATA device.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+
static void ata_pio_sector(struct ata_queued_cmd *qc)
{
int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
@@ -2594,6 +2676,18 @@
kunmap(page);
}
+/**
+ * __atapi_pio_bytes - Transfer data from/to the ATAPI device.
+ * @qc: Command on going
+ * @bytes: number of bytes
+ *
+ * Transfer Transfer data from/to the ATAPI device.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ *
+ */
+
static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
{
int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
@@ -2645,6 +2739,17 @@
}
}
+/**
+ * atapi_pio_bytes - Transfer data from/to the ATAPI device.
+ * @qc: Command on going
+ *
+ * Transfer Transfer data from/to the ATAPI device.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ *
+ */
+
static void atapi_pio_bytes(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH 2/2] libata handle the case when device returns/needs extra data
2005-08-12 6:09 [PATCH 0/2] libata PIO fixes (revised) Albert Lee
2005-08-12 6:15 ` [PATCH 1/2] libata ata_data_xfer() fix Albert Lee
@ 2005-08-12 6:17 ` Albert Lee
2005-08-12 6:45 ` [PATCH 0/2] libata PIO fixes (revised) Jeff Garzik
2 siblings, 0 replies; 4+ messages in thread
From: Albert Lee @ 2005-08-12 6:17 UTC (permalink / raw)
To: Jeff Garzik; +Cc: IDE Linux, Bartlomiej Zolnierkiewicz, Doug Maxey
[-- Attachment #1: Type: text/plain, Size: 394 bytes --]
Jeff,
PATCH 2/2:
Description:
Sometimes the device returns/needs extra data than expected.
Changes:
Modify __atapi_pio_bytes() to handle the case where device returns/needs extra data.
- for read case, discard trailing data from the device
- for write case, padding zero data to the device
For your review, thanks.
Albert
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
[-- Attachment #2: pio2.diff --]
[-- Type: text/plain, Size: 1240 bytes --]
--- 01_align/drivers/scsi/libata-core.c 2005-08-12 11:14:45.000000000 +0800
+++ 02_extra_data/drivers/scsi/libata-core.c 2005-08-12 11:14:04.000000000 +0800
@@ -2697,10 +2697,33 @@
unsigned char *buf;
unsigned int offset, count;
- if (qc->curbytes == qc->nbytes - bytes)
+ if (qc->curbytes + bytes >= qc->nbytes)
ap->pio_task_state = PIO_ST_LAST;
next_sg:
+ if (unlikely(qc->cursg >= qc->n_elem)) {
+ /*
+ * The end of qc->sg is reached and the device expects
+ * more data to transfer. In order not to overrun qc->sg
+ * and fulfill length specified in the byte count register,
+ * - for read case, discard trailing data from the device
+ * - for write case, padding zero data to the device
+ */
+ u16 pad_buf[1] = { 0 };
+ unsigned int words = bytes >> 1;
+ unsigned int i;
+
+ if (words) /* warning if bytes > 1 */
+ printk(KERN_WARNING "ata%u: %u bytes trailing data\n",
+ ap->id, bytes);
+
+ for (i = 0; i < words; i++)
+ ata_data_xfer(ap, (unsigned char*)pad_buf, 2, do_write);
+
+ ap->pio_task_state = PIO_ST_LAST;
+ return;
+ }
+
sg = &qc->sg[qc->cursg];
page = sg->page;
@@ -2734,9 +2757,8 @@
kunmap(page);
- if (bytes) {
+ if (bytes)
goto next_sg;
- }
}
/**
^ permalink raw reply [flat|nested] 4+ messages in thread