1 files changed, 26 insertions, 5 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index f69d1548b562..5ba96c5052c8 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1132,6 +1132,8 @@ void ata_id_string(const u16 *id, unsigned char *s,
 {
 	unsigned int c;
 
+	BUG_ON(len & 1);
+
 	while (len > 0) {
 		c = id[ofs] >> 8;
 		*s = c;
@@ -1165,8 +1167,6 @@ void ata_id_c_string(const u16 *id, unsigned char *s,
 {
 	unsigned char *p;
 
-	WARN_ON(!(len & 1));
-
 	ata_id_string(id, s, ofs, len - 1);
 
 	p = s + strnlen(s, len - 1);
@@ -1886,6 +1886,23 @@ static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
 }
 
 /**
+ *	ata_do_dev_read_id		-	default ID read method
+ *	@dev: device
+ *	@tf: proposed taskfile
+ *	@id: data buffer
+ *
+ *	Issue the identify taskfile and hand back the buffer containing
+ *	identify data. For some RAID controllers and for pre ATA devices
+ *	this function is wrapped or replaced by the driver
+ */
+unsigned int ata_do_dev_read_id(struct ata_device *dev,
+					struct ata_taskfile *tf, u16 *id)
+{
+	return ata_exec_internal(dev, tf, NULL, DMA_FROM_DEVICE,
+				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
+}
+
+/**
  *	ata_dev_read_id - Read ID data from the specified device
  *	@dev: target device
  *	@p_class: pointer to class of the target device (may be changed)
@@ -1920,7 +1937,7 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
 	if (ata_msg_ctl(ap))
 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __func__);
 
- retry:
+retry:
 	ata_tf_init(dev, &tf);
 
 	switch (class) {
@@ -1948,8 +1965,11 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
 	 */
 	tf.flags |= ATA_TFLAG_POLLING;
 
-	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
-				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
+	if (ap->ops->read_id)
+		err_mask = ap->ops->read_id(dev, &tf, id);
+	else
+		err_mask = ata_do_dev_read_id(dev, &tf, id);
+
 	if (err_mask) {
 		if (err_mask & AC_ERR_NODEV_HINT) {
 			ata_dev_printk(dev, KERN_DEBUG,
@@ -6283,6 +6303,7 @@ EXPORT_SYMBOL_GPL(ata_host_resume);
 #endif /* CONFIG_PM */
 EXPORT_SYMBOL_GPL(ata_id_string);
 EXPORT_SYMBOL_GPL(ata_id_c_string);
+EXPORT_SYMBOL_GPL(ata_do_dev_read_id);
 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
 
 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);