From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1ht7Fd-0005Y1-BG for barebox@lists.infradead.org; Thu, 01 Aug 2019 09:19:58 +0000 From: Bastian Krause Date: Thu, 1 Aug 2019 11:19:50 +0200 Message-Id: <20190801091950.14606-1-bst@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] mtd: spi-nor: fix page offset/remains calculation in spi_nor_write To: barebox@lists.infradead.org Cc: Steffen Trumtrar , Bastian Krause nor->write() simply adds the number of written bytes to the pointer given. Thus retval is incremented in each loop cycle for each spi_nor_write() call without ever resetting it. This leads to wrong page offset/remains calculations and an incorrect number of bytes written to retlen. This becomes apparant only if the calling function actually compares len and retlen (e.g. mtd_peb_write() ). Otherwise wrong data is written: $ memcpy -s /dev/prng -d prng_data 0 0 10k $ erase /dev/mtd0.mypart $ cp prng_data /dev/mtd0.mypart $ memcmp -s prng_data -d /dev/mtd0.mypart 0 0 memcmp returned "files differ" before, with this patch it returns "OK". Fixes: c8516869c4 ("spi: Extend the core to ease integration of SPI memory controllers") Signed-off-by: Bastian Krause --- drivers/mtd/spi-nor/spi-nor.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index b2052ce0af..9dbc8302ed 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -972,6 +972,7 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, for (i = 0; i < len; ) { ssize_t written; + retval = 0; page_offset = (to + i) & (nor->page_size - 1); page_remain = min_t(size_t, nor->page_size - page_offset, -- 2.20.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox