diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 49340dc1b10749dd0bff9300c1f013368d1dfe24..4e8e5fbc1e132c4934e95f8504f5d1eab7db5d84 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -366,20 +366,22 @@ static void mtdchar_erase_callback (struct erase_info *instr) static int otp_select_filemode(struct mtd_file_info *mfi, int mode) { struct mtd_info *mtd = mfi->mtd; + size_t retlen; int ret = 0; + /* + * Make a fake call to mtd_read_fact_prot_reg() to check if OTP + * operations are supported. + */ + if (mtd_read_fact_prot_reg(mtd, -1, -1, &retlen, NULL) == -EOPNOTSUPP) + return -EOPNOTSUPP; + switch (mode) { case MTD_OTP_FACTORY: - if (!mtd->read_fact_prot_reg) - ret = -EOPNOTSUPP; - else - mfi->mode = MTD_FILE_MODE_OTP_FACTORY; + mfi->mode = MTD_FILE_MODE_OTP_FACTORY; break; case MTD_OTP_USER: - if (!mtd->read_fact_prot_reg) - ret = -EOPNOTSUPP; - else - mfi->mode = MTD_FILE_MODE_OTP_USER; + mfi->mode = MTD_FILE_MODE_OTP_USER; break; default: ret = -EINVAL; diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 7122efdc6d99ca83118219b6ee63d09032c8635e..e488cf9109148eebef66686c7ad450ddf0421628 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -352,6 +352,8 @@ static inline int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, u_char *buf) { *retlen = 0; + if (!mtd->read_fact_prot_reg) + return -EOPNOTSUPP; return mtd->read_fact_prot_reg(mtd, from, len, retlen, buf); } @@ -369,6 +371,8 @@ static inline int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, u_char *buf) { *retlen = 0; + if (!mtd->read_user_prot_reg) + return -EOPNOTSUPP; return mtd->read_user_prot_reg(mtd, from, len, retlen, buf); }