+/**
+ * ata_set_mode - Program timings and issue SET FEATURES - XFER
+ * @link: link on which timings will be programmed
+ * @r_failed_dev: out paramter for failed device
+ *
+ * Set ATA device disk transfer mode (PIO3, UDMA6, etc.). If
+ * ata_set_mode() fails, pointer to the failing device is
+ * returned in @r_failed_dev.
+ *
+ * LOCKING:
+ * PCI/etc. bus probe sem.
+ *
+ * RETURNS:
+ * 0 on success, negative errno otherwise
+ */
+int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
+{
+ struct ata_port *ap = link->ap;
+ struct ata_device *dev;
+ int rc;
+
+ /* if data transfer is verified, clear DUBIOUS_XFER on ering top */
+ ata_for_each_dev(dev, link, ENABLED) {
+ if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
+ struct ata_ering_entry *ent;
+
+ ent = ata_ering_top(&dev->ering);
+ if (ent)
+ ent->eflags &= ~ATA_EFLAG_DUBIOUS_XFER;
+ }
+ }
+
+ /* has private set_mode? */
+ if (ap->ops->set_mode)
+ rc = ap->ops->set_mode(link, r_failed_dev);
+ else
+ rc = ata_do_set_mode(link, r_failed_dev);
+
+ /* if transfer mode has changed, set DUBIOUS_XFER on device */
+ ata_for_each_dev(dev, link, ENABLED) {
+ struct ata_eh_context *ehc = &link->eh_context;
+ u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
+ u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));
+
+ if (dev->xfer_mode != saved_xfer_mode ||
+ ata_ncq_enabled(dev) != saved_ncq)
+ dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
+ }
+
+ return rc;
+}
+
+/**
+ * atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
+ * @dev: ATAPI device to clear UA for
+ *
+ * Resets and other operations can make an ATAPI device raise
+ * UNIT ATTENTION which causes the next operation to fail. This
+ * function clears UA.
+ *
+ * LOCKING:
+ * EH context (may sleep).
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+static int atapi_eh_clear_ua(struct ata_device *dev)
+{
+ int i;
+
+ for (i = 0; i < ATA_EH_UA_TRIES; i++) {
+ u8 sense_buffer[SCSI_SENSE_BUFFERSIZE];
+ u8 sense_key = 0;
+ unsigned int err_mask;
+
+ err_mask = atapi_eh_tur(dev, &sense_key);
+ if (err_mask != 0 && err_mask != AC_ERR_DEV) {
+ ata_dev_printk(dev, KERN_WARNING, "TEST_UNIT_READY "
+ "failed (err_mask=0x%x)\n", err_mask);
+ return -EIO;
+ }
+
+ if (!err_mask || sense_key != UNIT_ATTENTION)
+ return 0;
+
+ err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
+ if (err_mask) {
+ ata_dev_printk(dev, KERN_WARNING, "failed to clear "
+ "UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
+ return -EIO;
+ }
+ }
+
+ ata_dev_printk(dev, KERN_WARNING,
+ "UNIT ATTENTION persists after %d tries\n", ATA_EH_UA_TRIES);
+
+ return 0;
+}
+