From e5d05cbd6d8b01f08c95c427a36c66aac769af4f Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Thu, 5 May 2016 17:31:54 -0700 Subject: mtd: spi-nor: simplify write loop The spi-nor write loop assumes that what is passed to the hardware driver write() is what gets written. When write() writes less than page size at once data is dropped on the floor. Check the amount of data writen and exit if it does not match requested amount. 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 | 58 +++++++++++++++++++------------------------ 1 file changed, 25 insertions(+), 33 deletions(-) (limited to 'drivers/mtd/spi-nor/spi-nor.c') diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index 34dd95373e77..fe55b48be5b3 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -1129,8 +1129,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { struct spi_nor *nor = mtd_to_spi_nor(mtd); - u32 page_offset, page_size, i; - int ret; + size_t page_offset, page_remain, i; + ssize_t ret; dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len); @@ -1138,45 +1138,37 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, if (ret) return ret; - write_enable(nor); - - page_offset = to & (nor->page_size - 1); + for (i = 0; i < len; ) { + ssize_t written; - /* do all the bytes fit onto one page? */ - if (page_offset + len <= nor->page_size) { - ret = nor->write(nor, to, len, buf); - if (ret < 0) - goto write_err; - *retlen += ret; - } else { + page_offset = (to + i) & (nor->page_size - 1); + WARN_ONCE(page_offset, + "Writing at offset %zu into a NOR page. Writing partial pages may decrease reliability and increase wear of NOR flash.", + page_offset); /* the size of data remaining on the first page */ - page_size = nor->page_size - page_offset; - ret = nor->write(nor, to, page_size, buf); + page_remain = min_t(size_t, + nor->page_size - page_offset, len - i); + + write_enable(nor); + ret = nor->write(nor, to + i, page_remain, buf + i); if (ret < 0) goto write_err; - *retlen += ret; - - /* write everything in nor->page_size chunks */ - for (i = ret; i < len; ) { - page_size = len - i; - if (page_size > nor->page_size) - page_size = nor->page_size; - - ret = spi_nor_wait_till_ready(nor); - if (ret) - goto write_err; + written = ret; - write_enable(nor); - - ret = nor->write(nor, to + i, page_size, buf + i); - if (ret < 0) - goto write_err; - *retlen += ret; - i += ret; + ret = spi_nor_wait_till_ready(nor); + if (ret) + goto write_err; + *retlen += written; + i += written; + if (written != page_remain) { + dev_err(nor->dev, + "While writing %zu bytes written %zd bytes\n", + page_remain, written); + ret = -EIO; + goto write_err; } } - ret = spi_nor_wait_till_ready(nor); write_err: spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE); return ret; -- cgit v1.2.3-55-g7522