diff options
Diffstat (limited to 'target/linux/brcm63xx/patches-4.4/000-4.8-08-mtd-spi-nor-simplify-write-loop.patch')
| -rw-r--r-- | target/linux/brcm63xx/patches-4.4/000-4.8-08-mtd-spi-nor-simplify-write-loop.patch | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/target/linux/brcm63xx/patches-4.4/000-4.8-08-mtd-spi-nor-simplify-write-loop.patch b/target/linux/brcm63xx/patches-4.4/000-4.8-08-mtd-spi-nor-simplify-write-loop.patch new file mode 100644 index 0000000000..b2e840d488 --- /dev/null +++ b/target/linux/brcm63xx/patches-4.4/000-4.8-08-mtd-spi-nor-simplify-write-loop.patch @@ -0,0 +1,103 @@ +From e5d05cbd6d8b01f08c95c427a36c66aac769af4f Mon Sep 17 00:00:00 2001 +From: Michal Suchanek <hramrach@gmail.com> +Date: Thu, 5 May 2016 17:31:54 -0700 +Subject: [PATCH 08/10] 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 <hramrach@gmail.com> +Signed-off-by: Brian Norris <computersforpeace@gmail.com> +Tested-by Cyrille Pitchen <cyrille.pitchen@atmel.com> +Acked-by: Michal Suchanek <hramrach@gmail.com> +Tested-by: Michal Suchanek <hramrach@gmail.com> +--- + drivers/mtd/spi-nor/spi-nor.c | 58 +++++++++++++++++++------------------------ + 1 file changed, 25 insertions(+), 33 deletions(-) + +--- a/drivers/mtd/spi-nor/spi-nor.c ++++ b/drivers/mtd/spi-nor/spi-nor.c +@@ -988,8 +988,8 @@ static int spi_nor_write(struct mtd_info + 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); + +@@ -997,45 +997,37 @@ static int spi_nor_write(struct mtd_info + if (ret) + return ret; + +- write_enable(nor); ++ for (i = 0; i < len; ) { ++ ssize_t written; + +- page_offset = to & (nor->page_size - 1); +- +- /* 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; ++ written = 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; +- +- 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; |