From 26f9bcad29a6c240881bd4efc90f16a9990dd6c2 Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Thu, 5 May 2016 17:31:55 -0700 Subject: [PATCH 09/10] mtd: spi-nor: add read loop mtdblock and ubi do not handle the situation when read returns less data than requested. Loop in spi-nor until buffer is filled or an error is returned. Signed-off-by: Michal Suchanek Signed-off-by: Brian Norris Tested-by Cyrille Pitchen Acked-by: Michal Suchanek Tested-by: Michal Suchanek --- drivers/mtd/spi-nor/spi-nor.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -890,14 +890,27 @@ static int spi_nor_read(struct mtd_info if (ret) return ret; - ret = nor->read(nor, from, len, buf); + while (len) { + ret = nor->read(nor, from, len, buf); + if (ret == 0) { + /* We shouldn't see 0-length reads */ + ret = -EIO; + goto read_err; + } + if (ret < 0) + goto read_err; - spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ); - if (ret < 0) - return ret; + WARN_ON(ret > len); + *retlen += ret; + buf += ret; + from += ret; + len -= ret; + } + ret = 0; - *retlen += ret; - return 0; +read_err: + spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ); + return ret; } static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,