From 07300164657526d8d26c626c43723c310fbf3616 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Fri, 9 Nov 2012 16:23:45 +0800 Subject: [PATCH] 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 Signed-off-by: Artem Bityutskiy --- drivers/mtd/nand/nand_base.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 01505406ca7b..95d56ed8500a 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -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; -- 2.20.1