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-rw-r--r--drivers/ata/libata-eh.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 33ac5ea..f2dd991 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -79,6 +79,8 @@ enum {
*/
ATA_EH_PRERESET_TIMEOUT = 10000,
ATA_EH_FASTDRAIN_INTERVAL = 3000,
+
+ ATA_EH_UA_TRIES = 5,
};
/* The following table determines how we sequence resets. Each entry
@@ -1357,6 +1359,37 @@ static int ata_eh_read_log_10h(struct ata_device *dev,
}
/**
+ * atapi_eh_tur - perform ATAPI TEST_UNIT_READY
+ * @dev: target ATAPI device
+ * @r_sense_key: out parameter for sense_key
+ *
+ * Perform ATAPI TEST_UNIT_READY.
+ *
+ * LOCKING:
+ * EH context (may sleep).
+ *
+ * RETURNS:
+ * 0 on success, AC_ERR_* mask on failure.
+ */
+static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
+{
+ u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
+ struct ata_taskfile tf;
+ unsigned int err_mask;
+
+ ata_tf_init(dev, &tf);
+
+ tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
+ tf.command = ATA_CMD_PACKET;
+ tf.protocol = ATAPI_PROT_NODATA;
+
+ err_mask = ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
+ if (err_mask == AC_ERR_DEV)
+ *r_sense_key = tf.feature >> 4;
+ return err_mask;
+}
+
+/**
* atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
* @dev: device to perform REQUEST_SENSE to
* @sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long)
@@ -2774,6 +2807,53 @@ int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
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;
+}
+
static int ata_link_nr_enabled(struct ata_link *link)
{
struct ata_device *dev;
@@ -3066,6 +3146,20 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
ehc->i.flags &= ~ATA_EHI_SETMODE;
}
+ /* If reset has been issued, clear UA to avoid
+ * disrupting the current users of the device.
+ */
+ if (ehc->i.flags & ATA_EHI_DID_RESET) {
+ ata_link_for_each_dev(dev, link) {
+ if (dev->class != ATA_DEV_ATAPI)
+ continue;
+ rc = atapi_eh_clear_ua(dev);
+ if (rc)
+ goto dev_fail;
+ }
+ }
+
+ /* configure link power saving */
if (ehc->i.action & ATA_EH_LPM)
ata_link_for_each_dev(dev, link)
ata_dev_enable_pm(dev, ap->pm_policy);