[RFT PATCH v1 4/5] usb: Provide code to handle spinup of USB usb devices (mostly HDDs)

[Lukasz Majewski]

After this change USB mass storage devices - mostly HDDs connected via USB
- will gain handling of extra time needed for their spin up.

This operation is realized with issuing SCSI start/stop unit (0x1B) command.

This code is the port to newest U-Boot of the fix from - "rayvt" (from [1]).

Links:
[1] - https://forum.doozan.com/read.php?3,35295,35295#msg-35295
[2] - https://www.dropbox.com/s/nrkrd1no63viuu8/uboot-bodhi-2016.05-timeoutTD.patch?dl=0

Signed-off-by: Lukasz Majewski <lukma at denx.de>
[Unfortunately, the original patch [2] did not contain S-o-B from the original
author - "rayvt"]
---

 common/usb_storage.c | 36 ++++++++++++++++++++++++++++++++++++
 include/usb.h        |  1 +
 2 files changed, 37 insertions(+)

diff --git a/common/usb_storage.c b/common/usb_storage.c
index 92e1e54d1c..3c2324fa1a 100644
--- a/common/usb_storage.c
+++ b/common/usb_storage.c
@@ -729,6 +729,7 @@ static int usb_stor_BBB_transport(struct scsi_cmd *srb, struct us_data *us)
 	pipeout = usb_sndbulkpipe(us->pusb_dev, us->ep_out);
 	/* DATA phase + error handling */
 	data_actlen = 0;
+	mdelay(10);		/* Like linux does. */
 	/* no data, go immediately to the STATUS phase */
 	if (srb->datalen == 0)
 		goto st;
@@ -1023,9 +1024,32 @@ static int usb_request_sense(struct scsi_cmd *srb, struct us_data *ss)
 	return 0;
 }
 
+/*
+ * This spins up the disk and also consumes the time that the
+ * disk takes to become active and ready to read data.
+ * Some drives (like Western Digital) can take more than 5 seconds.
+ * The delay occurs on the 1st data read from the disk.
+ * Extending the timeout here works better than handling the timeout
+ * as an error on a "real" read.
+ */
+static int usb_spinup(struct scsi_cmd *srb, struct us_data *ss)
+{
+	memset(&srb->cmd[0], 0, 12);
+	srb->cmd[0] = SCSI_START_STP;
+	srb->cmd[1] = srb->lun << 5;
+	srb->cmd[4] = 1;	/* Start spinup. */
+	srb->datalen = 0;
+	srb->cmdlen = 6;
+	ss->pusb_dev->extra_timeout = 9876;
+	ss->transport(srb, ss);
+	ss->pusb_dev->extra_timeout = 0;
+	return 0;
+}
+
 static int usb_test_unit_ready(struct scsi_cmd *srb, struct us_data *ss)
 {
 	int retries = 10;
+	int gave_extra_time = 0;
 
 	do {
 		memset(&srb->cmd[0], 0, 12);
@@ -1048,6 +1072,17 @@ static int usb_test_unit_ready(struct scsi_cmd *srb, struct us_data *ss)
 		if ((srb->sense_buf[2] == 0x02) &&
 		    (srb->sense_buf[12] == 0x3a))
 			return -1;
+		/*
+		 * If the status is "Not Ready - becoming ready", give it
+		 * more time.  Linux issues a spinup command (once) and gives
+		 * it 100 seconds.
+		 */
+		if (srb->sense_buf[2] == 0x02 &&
+		    srb->sense_buf[12] == 0x04 &&
+		    gave_extra_time == 0) {
+			retries = 100; /* Allow 10 seconds. */
+			gave_extra_time = retries;
+		}
 		mdelay(100);
 	} while (retries--);
 
@@ -1502,6 +1537,7 @@ int usb_stor_get_info(struct usb_device *dev, struct us_data *ss,
 	dev_desc->log2blksz = LOG2(dev_desc->blksz);
 	dev_desc->type = perq;
 	debug(" address %d\n", dev_desc->target);
+	usb_spinup(pccb, ss);
 
 	return 1;
 }
diff --git a/include/usb.h b/include/usb.h
index efb67ea33f..5b0f5ce5d6 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -140,6 +140,7 @@ struct usb_device {
 	int act_len;			/* transferred bytes */
 	int maxchild;			/* Number of ports if hub */
 	int portnr;			/* Port number, 1=first */
+	int extra_timeout; /* Add to timeout in ehci_submit_async or spinup */
 #if !CONFIG_IS_ENABLED(DM_USB)
 	/* parent hub, or NULL if this is the root hub */
 	struct usb_device *parent;
-- 
2.20.1