[U-Boot] [PATCH 6/7] dm: scsi: fix scan

[Jean-Jacques Hiblot]

With DM_SCSI enabled, scsi scan suffers 2 problems:
* blk_create_devicef is called with blkz = 0, leading to a divide-by-0
  exception
* new blk devices are created at each scan.

To fix this we start by removing all known SCSI devices at the beginning
of the scan. Then a detection process is started for each possible
device only to get the blksz and lba of the device (no call to part_init() yet).
If a device is found, we can call blk_create_devicef() with the right
parameters and continue the process.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
---
 common/scsi.c | 35 +++++++++++++++++++++++++++++------
 1 file changed, 29 insertions(+), 6 deletions(-)

diff --git a/common/scsi.c b/common/scsi.c
index fb5b407..3385cc2 100644
--- a/common/scsi.c
+++ b/common/scsi.c
@@ -480,7 +480,7 @@ static void scsi_init_dev_desc(struct blk_desc *dev_desc, int devnum)
  *
  * Return: 0 on success, error value otherwise
  */
-static int scsi_detect_dev(int target, struct blk_desc *dev_desc)
+static int scsi_detect_dev(int target, struct blk_desc *dev_desc, int init_part)
 {
 	unsigned char perq, modi;
 	lbaint_t capacity;
@@ -539,7 +539,8 @@ static int scsi_detect_dev(int target, struct blk_desc *dev_desc)
 	dev_desc->blksz = blksz;
 	dev_desc->log2blksz = LOG2(dev_desc->blksz);
 	dev_desc->type = perq;
-	part_init(&dev_desc[0]);
+	if (init_part)
+		part_init(&dev_desc[0]);
 removable:
 	return 0;
 }
@@ -565,6 +566,9 @@ int scsi_scan(int mode)
 	if (ret)
 		return ret;
 
+	/* remove all SCSI interfaces since we're going to (re)create them */
+	blk_unbind_all(IF_TYPE_SCSI);
+
 	uclass_foreach_dev(dev, uc) {
 		struct scsi_platdata *plat; /* scsi controller platdata */
 
@@ -580,9 +584,20 @@ int scsi_scan(int mode)
 			for (lun = 0; lun < plat->max_lun; lun++) {
 				struct udevice *bdev; /* block device */
 				/* block device description */
+				struct blk_desc _bd;
 				struct blk_desc *bdesc;
 				char str[10];
 
+				scsi_init_dev_desc_priv(&_bd);
+				_bd.lun = lun;
+				ret = scsi_detect_dev(i, &_bd, 0);
+				if (ret)
+					/*
+					 * no device detected?
+					 * check the next lun.
+					 */
+					continue;
+
 				/*
 				 * Create only one block device and do detection
 				 * to make sure that there won't be a lot of
@@ -590,17 +605,25 @@ int scsi_scan(int mode)
 				 */
 				snprintf(str, sizeof(str), "id%dlun%d", i, lun);
 				ret = blk_create_devicef(dev, "scsi_blk",
-							  str, IF_TYPE_SCSI,
-							  -1, 0, 0, &bdev);
+						str, IF_TYPE_SCSI,
+						-1,
+						_bd.blksz,
+						_bd.blksz * _bd.lba,
+						&bdev);
 				if (ret) {
 					debug("Can't create device\n");
 					return ret;
 				}
 				bdesc = dev_get_uclass_platdata(bdev);
 
+				/*
+				 * perform the detection once more but this
+				 * time, let's initialize do the initialization
+				 * of the partitions
+				 */
 				scsi_init_dev_desc_priv(bdesc);
 				bdesc->lun = lun;
-				ret = scsi_detect_dev(i, bdesc);
+				ret = scsi_detect_dev(i, bdesc, 1);
 				if (ret) {
 					device_unbind(bdev);
 					continue;
@@ -631,7 +654,7 @@ int scsi_scan(int mode)
 	for (i = 0; i < CONFIG_SYS_SCSI_MAX_SCSI_ID; i++) {
 		for (lun = 0; lun < CONFIG_SYS_SCSI_MAX_LUN; lun++) {
 			scsi_dev_desc[scsi_max_devs].lun = lun;
-			ret = scsi_detect_dev(i, &scsi_dev_desc[scsi_max_devs]);
+			ret = scsi_detect_dev(i, &scsi_dev_desc[scsi_max_devs], 1);
 			if (ret)
 				continue;
 
-- 
1.9.1