diff options
authorMasahiro Yamada <yamada.masahiro@socionext.com>2018-08-27 16:01:41 +0900
committerBoris Brezillon <boris.brezillon@bootlin.com>2018-08-27 20:41:46 +0200
commit336d139f8718b1336c9d22f0e462611ae1229850 (patch)
parent166cd4421b0dabd2e438f5384f4ecf930dc8ab08 (diff)
mtd: rawnand: denali: do not pass zero maxchips to nand_scan()
Commit 49aa76b16676 ("mtd: rawnand: do not execute nand_scan_ident() if maxchips is zero") gave a new meaning for calling nand_scan_ident() with maxchips=0. It is a special usage for some drivers such as docg4, but actually the Denali driver may pass maxchips=0 to nand_scan() when the driver is enabled but no NAND chip is found on the board for some reasons. If nand_scan_with_ids() is called with maxchips=0, nand_scan_ident() is skipped, then nand_set_defaults() is skipped as well. Thus, the driver must set chip->controller beforehand. Otherwise, nand_attach() causes NULL pointer dereference. In fact, the Denali controller knows the number of connected chips before calling nand_scan_ident(); if DEVICE_RESET fails, there is no chip in that chip select. Then, denali_reset_banks() sets the maxchips to the number of detected chips. If no chip is found, maxchips is zero. In this case, there is no point for calling nand_scan() because we know it will fail for sure. Let's make the probe function fail immediately. Fixes: 49aa76b16676 ("mtd: rawnand: do not execute nand_scan_ident() if maxchips is zero") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/denali.c b/drivers/mtd/nand/raw/denali.c
index ca18612c4201..67b2065e7a19 100644
--- a/drivers/mtd/nand/raw/denali.c
+++ b/drivers/mtd/nand/raw/denali.c
@@ -1338,6 +1338,11 @@ int denali_init(struct denali_nand_info *denali)
+ if (!denali->max_banks) {
+ /* Error out earlier if no chip is found for some reasons. */
+ ret = -ENODEV;
+ goto disable_irq;
+ }
denali->active_bank = DENALI_INVALID_BANK;