Commit ad245789 authored by Daniel Mack's avatar Daniel Mack Committed by David Woodhouse
Browse files

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: default avatarDaniel Mack <zonque@gmail.com>
Acked-by: default avatarPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 0cca9fbf

drivers/mtd/devices/elm.c

+8 −1
Original line number Diff line number Diff line
@@ -81,14 +81,21 @@ static u32 elm_read_reg(struct elm_info *info, int offset) 
 * @dev:	ELM device

 * @bch_type:	Type of BCH ecc

 */

void elm_config(struct device *dev, enum bch_ecc bch_type)

int 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 -ENODEV;

	}



	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;



	return 0;

}

EXPORT_SYMBOL(elm_config);

drivers/mtd/nand/omap2.c

+3 −2
Original line number Diff line number Diff line
@@ -1701,7 +1701,8 @@ 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);



		if (elm_config(info->elm_dev, bch_type) == 0)

			info->is_elm_used = true;

	}

include/linux/platform_data/elm.h

+1 −1
Original line number Diff line number Diff line
@@ -50,5 +50,5 @@ struct elm_errorvec { 


void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc,

		struct elm_errorvec *err_vec);

void elm_config(struct device *dev, enum bch_ecc bch_type);

int elm_config(struct device *dev, enum bch_ecc bch_type);

#endif /* __ELM_H */

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