mtd: de-select the chip when it is not used
When we scan several nand chips with nand_scan(), such as
.......................
nand_scan(*, 2);
.......................
In nand_scan_ident(), the maxchips will become 2, so the current code
will select chip 1 to read the device ID. But the chip 0 is still
selected in this case.
To make the logic clear, we'd better de-select the chip when it is not used.
This patch de-select the nand chip if it is not used any more.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 0150540..95d56ed 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3329,6 +3329,8 @@
return PTR_ERR(type);
}
+ chip->select_chip(mtd, -1);
+
/* Check for a chip array */
for (i = 1; i < maxchips; i++) {
chip->select_chip(mtd, i);
@@ -3338,8 +3340,11 @@
chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
/* Read manufacturer and device IDs */
if (nand_maf_id != chip->read_byte(mtd) ||
- nand_dev_id != chip->read_byte(mtd))
+ nand_dev_id != chip->read_byte(mtd)) {
+ chip->select_chip(mtd, -1);
break;
+ }
+ chip->select_chip(mtd, -1);
}
if (i > 1)
pr_info("%d NAND chips detected\n", i);
@@ -3598,9 +3603,6 @@
/* Initialize state */
chip->state = FL_READY;
- /* De-select the device */
- chip->select_chip(mtd, -1);
-
/* Invalidate the pagebuffer reference */
chip->pagebuf = -1;