[PATCH v3 27/32] mtd: spi-nor: Extend the QE Read Back test to both SR1 and SR2

[Tudor.Ambarus]

From: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>

In case of 16-bit Write Status Register, check that both SR1 and
SR2 were written correctly.

Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
---
 drivers/mtd/spi-nor/spi-nor.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 55a12a1d710e..eecbd161df25 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2067,6 +2067,7 @@ static int spansion_no_read_cr_quad_enable(struct spi_nor *nor)
 {
 	u8 *sr_cr = nor->bouncebuf;
 	int ret;
+	u8 sr_written;
 
 	/* Keep the current value of the Status Register. */
 	ret = spi_nor_read_sr(nor, &sr_cr[0]);
@@ -2075,7 +2076,22 @@ static int spansion_no_read_cr_quad_enable(struct spi_nor *nor)
 
 	sr_cr[1] = CR_QUAD_EN_SPAN;
 
-	return spi_nor_write_sr(nor, sr_cr, 2);
+	ret = spi_nor_write_sr(nor, sr_cr, 2);
+	if (ret)
+		return ret;
+
+	sr_written = sr_cr[0];
+
+	ret = spi_nor_read_sr(nor, &sr_cr[0]);
+	if (ret)
+		return ret;
+
+	if (sr_cr[0] != sr_written) {
+		dev_err(nor->dev, "SR1: Read back test failed\n");
+		return -EIO;
+	}
+
+	return 0;
 }
 
 /**
@@ -2116,6 +2132,17 @@ static int spansion_read_cr_quad_enable(struct spi_nor *nor)
 	if (ret)
 		return ret;
 
+	sr_written = sr_cr[0];
+
+	ret = spi_nor_read_sr(nor, &sr_cr[0]);
+	if (ret)
+		return ret;
+
+	if (sr_written != sr_cr[0]) {
+		dev_err(nor->dev, "SR1: Read back test failed\n");
+		return -EIO;
+	}
+
 	sr_written = sr_cr[1];
 
 	/* Read back and check it. */
-- 
2.9.5