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. Better bail out with a warning in such cases.

---
 drivers/mtd/devices/elm.c | 5 +++++
 1 file changed, 5 insertions(+)

index 2ec5da9..a9b6d04 100644
@@ -86,6 +86,11 @@ void elm_config(struct device *dev, enum bch_ecc bch_type)
 	u32 reg_val;
 	struct elm_info *info = dev_get_drvdata(dev);
 
+	if (!info) {
+		dev_err(dev, "Unable to configure elm - device not probed?\n");
+		return;
+	}
+
 	reg_val = (bch_type & ECC_BCH_LEVEL_MASK) | (ELM_ECC_SIZE << 16);
 	elm_write_reg(info, ELM_LOCATION_CONFIG, reg_val);
 	info->bch_type = bch_type;

1.8.1.4

Daniel> In case the driver is not probed - due to config mismatches or errors Daniel> in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops Daniel> during boot. Better bail out with a warning in such cases.

Daniel> Signed-off-by: Daniel Mack <[email protected]> Daniel> Cc: Philip Avinash <[email protected]> Daniel> Cc: Artem Bityutskiy <[email protected]> Daniel> ---

 Daniel>  drivers/mtd/devices/elm.c | 5 +++++

Daniel> 1 file changed, 5 insertions(+)

Daniel> diff --git a/drivers/mtd/devices/elm.c b/drivers/mtd/devices/elm.c Daniel> index 2ec5da9..a9b6d04 100644
Daniel> --- a/drivers/mtd/devices/elm.c
Daniel> +++ b/drivers/mtd/devices/elm.c
Daniel> @@ -86,6 +86,11 @@ void elm_config(struct device *dev, enum bch_ecc bch_type)
Daniel> u32 reg_val;
Daniel> struct elm_info *info = dev_get_drvdata(dev);

Daniel> + if (!info) {
Daniel> + dev_err(dev, "Unable to configure elm - device not probed?\n");
Daniel> + return;
Daniel> + }
Daniel> +

Even better would be to propagate the error message (E.G. return -ENODEV) and let omap2.c deal with it (fall back to sw).

Bye, Peter Korsgaard

Yes, you're right. Will send an updated version later ...

Thanks,
Daniel