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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>
This commit is contained in:
Huang Shijie 2012-11-09 16:23:45 +08:00 committed by Artem Bityutskiy
parent ded4c55d10
commit 0730016465
1 changed files with 6 additions and 4 deletions
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10
drivers/mtd/nand/nand_base.c
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@ -3329,6 +3329,8 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
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 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
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 @@ int nand_scan_tail(struct mtd_info *mtd)
/* Initialize state */
chip->state = FL_READY;
/* De-select the device */
chip->select_chip(mtd, -1);
/* Invalidate the pagebuffer reference */
chip->pagebuf = -1;