mtd: devices: elm: check for device's presence before configuration

In case the driver is not probed - due to config mismatches or errors
in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops
during boot.

Make elm_config() return an error in such cases to propagate the error
up to the user, so it can fall back to software mode.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 8e820ddf4e08..b97ef3b68ec6 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1701,8 +1701,9 @@ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
                 elm_node = of_find_node_by_phandle(be32_to_cpup(parp));
                 pdev = of_find_device_by_node(elm_node);
                 info->elm_dev = &pdev->dev;
-                elm_config(info->elm_dev, bch_type);
-                info->is_elm_used = true;
+
+                if (elm_config(info->elm_dev, bch_type) == 0)
+                        info->is_elm_used = true;
         }
 
         if (info->is_elm_used && (mtd->writesize <= 4096)) {