mtd: spi-nor: check return value from write

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=0bad7b9304d543dd7627f4cd564aea5d7338b950
Commit:     0bad7b9304d543dd7627f4cd564aea5d7338b950
Parent:     bc418cd2652f47a327e27f978caa3d85f9558b09
Author:     Michal Suchanek <hramrach at gmail.com>
AuthorDate: Thu May 5 17:31:52 2016 -0700
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Wed Jun 1 17:22:46 2016 -0700

    mtd: spi-nor: check return value from write
    
    SPI NOR hardware drivers now return useful value from their write
    functions so check them.
    
    Signed-off-by: Michal Suchanek <hramrach at gmail.com>
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
    Tested-by Cyrille Pitchen <cyrille.pitchen at atmel.com>
    Acked-by: Michal Suchanek <hramrach at gmail.com>
    Tested-by: Michal Suchanek <hramrach at gmail.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 45 ++++++++++++++++++++++++++++++-------------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 6c92b95..f204d29 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1063,10 +1063,14 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		nor->program_opcode = SPINOR_OP_BP;
 
 		/* write one byte. */
-		nor->write(nor, to, 1, retlen, buf);
+		ret = nor->write(nor, to, 1, retlen, buf);
+		if (ret < 0)
+			goto sst_write_err;
+		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
+		     (int)ret);
 		ret = spi_nor_wait_till_ready(nor);
 		if (ret)
-			goto time_out;
+			goto sst_write_err;
 	}
 	to += actual;
 
@@ -1075,10 +1079,14 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		nor->program_opcode = SPINOR_OP_AAI_WP;
 
 		/* write two bytes. */
-		nor->write(nor, to, 2, retlen, buf + actual);
+		ret = nor->write(nor, to, 2, retlen, buf + actual);
+		if (ret < 0)
+			goto sst_write_err;
+		WARN(ret != 2, "While writing 2 bytes written %i bytes\n",
+		     (int)ret);
 		ret = spi_nor_wait_till_ready(nor);
 		if (ret)
-			goto time_out;
+			goto sst_write_err;
 		to += 2;
 		nor->sst_write_second = true;
 	}
@@ -1087,21 +1095,24 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 	write_disable(nor);
 	ret = spi_nor_wait_till_ready(nor);
 	if (ret)
-		goto time_out;
+		goto sst_write_err;
 
 	/* Write out trailing byte if it exists. */
 	if (actual != len) {
 		write_enable(nor);
 
 		nor->program_opcode = SPINOR_OP_BP;
-		nor->write(nor, to, 1, retlen, buf + actual);
-
+		ret = nor->write(nor, to, 1, retlen, buf + actual);
+		if (ret < 0)
+			goto sst_write_err;
+		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
+		     (int)ret);
 		ret = spi_nor_wait_till_ready(nor);
 		if (ret)
-			goto time_out;
+			goto sst_write_err;
 		write_disable(nor);
 	}
-time_out:
+sst_write_err:
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
 	return ret;
 }
@@ -1130,14 +1141,18 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	/* do all the bytes fit onto one page? */
 	if (page_offset + len <= nor->page_size) {
-		nor->write(nor, to, len, retlen, buf);
+		ret = nor->write(nor, to, len, retlen, buf);
+		if (ret < 0)
+			goto write_err;
 	} else {
 		/* the size of data remaining on the first page */
 		page_size = nor->page_size - page_offset;
-		nor->write(nor, to, page_size, retlen, buf);
+		ret = nor->write(nor, to, page_size, retlen, buf);
+		if (ret < 0)
+			goto write_err;
 
 		/* write everything in nor->page_size chunks */
-		for (i = page_size; i < len; i += page_size) {
+		for (i = ret; i < len; ) {
 			page_size = len - i;
 			if (page_size > nor->page_size)
 				page_size = nor->page_size;
@@ -1148,7 +1163,11 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 			write_enable(nor);
 
-			nor->write(nor, to + i, page_size, retlen, buf + i);
+			ret = nor->write(nor, to + i, page_size, retlen,
+					 buf + i);
+			if (ret < 0)
+				goto write_err;
+			i += ret;
 		}
 	}