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mtd: nand: Error out if cmd_ctrl() is missing

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If no user specified chip->select_chip() function is provided, code in
nand_base.c will automatically set this hook to nand_select_chip(),
which in turn depends on chip->cmd_ctrl() hook being valid. Not
providing both of those functions in NAND controller driver (for example
by mistake) will result in a bit cryptic segfault. Same is true for
chip->cmdfunc().

To avoid the above scenario add a check in nand_scan_dent and error out
if cmd_ctrl() is not provided.

Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Suggested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
This commit is contained in:
Andrey Smirnov 2016-07-21 14:59:20 -07:00 committed by Boris Brezillon
parent 75c19e58ab
commit 76fe334f71
1 changed files with 9 additions and 0 deletions
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9
drivers/mtd/nand/nand_base.c
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@ -4140,6 +4140,15 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
if (!mtd->name && mtd->dev.parent)
mtd->name = dev_name(mtd->dev.parent);
if ((!chip->cmdfunc || !chip->select_chip) && !chip->cmd_ctrl) {
/*
* Default functions assigned for chip_select() and
* cmdfunc() both expect cmd_ctrl() to be populated,
* so we need to check that that's the case
*/
pr_err("chip.cmd_ctrl() callback is not provided");
return -EINVAL;
}
/* Set the default functions */
nand_set_defaults(chip, chip->options & NAND_BUSWIDTH_16);