From ad2457894c272279bf73ca46ae5ea5de4876d2a0 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Mon, 4 Mar 2013 00:57:20 +0100 Subject: [PATCH] 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 Acked-by: Peter Korsgaard Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/devices/elm.c | 9 ++++++++- drivers/mtd/nand/omap2.c | 5 +++-- include/linux/platform_data/elm.h | 2 +- 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/devices/elm.c b/drivers/mtd/devices/elm.c index 2ec5da9ee248..dccef9fdc1f2 100644 --- a/drivers/mtd/devices/elm.c +++ b/drivers/mtd/devices/elm.c @@ -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); 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)) { diff --git a/include/linux/platform_data/elm.h b/include/linux/platform_data/elm.h index 1bd5244d1dcd..bf0a83b7ed9d 100644 --- a/include/linux/platform_data/elm.h +++ b/include/linux/platform_data/elm.h @@ -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 */ -- 2.20.1