From fef775caa705255358cdf7bbaf9bbc2fd1111761 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ezequiel=20Garc=C3=ADa?= Date: Thu, 11 Sep 2014 12:02:08 -0300 Subject: nand: omap2: Add support for flash-based bad block table This commit adds a new platform-data boolean property that enables use of a flash-based bad block table. This can also be enabled by setting the 'nand-on-flash-bbt' devicetree property. If the flash BBT is not enabled, the driver falls back to use OOB bad block markers only, as before. If the flash BBT is enabled the kernel will keep track of bad blocks using a BBT, in addition to the OOB markers. As explained by Brian Norris the reasons for using a BBT are: "" The primary reason would be that NAND datasheets specify it these days. A better argument is that nobody guarantees that you can write a bad block marker to a worn out block; you may just get program failures. This has been acknowledged by several developers over the last several years. Additionally, you get a boot-time performance improvement if you only have to read a few pages, instead of a page or two from every block on the flash. "" Signed-off-by: Ezequiel Garcia Acked-by: Roger Quadros Signed-off-by: Brian Norris --- include/linux/platform_data/mtd-nand-omap2.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/platform_data') diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h index 16ec262dfcc8..090bbab0130a 100644 --- a/include/linux/platform_data/mtd-nand-omap2.h +++ b/include/linux/platform_data/mtd-nand-omap2.h @@ -71,6 +71,7 @@ struct omap_nand_platform_data { struct mtd_partition *parts; int nr_parts; bool dev_ready; + bool flash_bbt; enum nand_io xfer_type; int devsize; enum omap_ecc ecc_opt; -- cgit v1.2.3 From 93af53b8633c4cb474585158512182b21219d743 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ezequiel=20Garc=C3=ADa?= Date: Sat, 20 Sep 2014 17:53:12 +0100 Subject: nand: omap2: Remove horrible ifdefs to fix module probe The current code abuses ifdefs to determine if the selected ECC scheme is supported by the running kernel. As a result the code is hard to read, and it also fails to load as a module. This commit removes all the ifdefs and instead introduces a function omap2_nand_ecc_check() to check if the ECC is supported by using IS_ENABLED(CONFIG_xxx). Since IS_ENABLED() is true when a config is =y or =m, this change fixes the module so it can be loaded with no issues. Acked-by: Roger Quadros Signed-off-by: Ezequiel Garcia Signed-off-by: Brian Norris --- include/linux/platform_data/elm.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux/platform_data') diff --git a/include/linux/platform_data/elm.h b/include/linux/platform_data/elm.h index 780d1e97f620..b8686c00f15f 100644 --- a/include/linux/platform_data/elm.h +++ b/include/linux/platform_data/elm.h @@ -42,8 +42,24 @@ struct elm_errorvec { int error_loc[16]; }; +#if IS_ENABLED(CONFIG_MTD_NAND_OMAP_BCH) void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc, struct elm_errorvec *err_vec); int elm_config(struct device *dev, enum bch_ecc bch_type, int ecc_steps, int ecc_step_size, int ecc_syndrome_size); +#else +static inline void +elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc, + struct elm_errorvec *err_vec) +{ +} + +static inline int elm_config(struct device *dev, enum bch_ecc bch_type, + int ecc_steps, int ecc_step_size, + int ecc_syndrome_size) +{ + return -ENOSYS; +} +#endif /* CONFIG_MTD_NAND_ECC_BCH */ + #endif /* __ELM_H */ -- cgit v1.2.3