[PATCH v4 1/8] mtd: spi-nor: improve macronix_quad_enable()

[Cyrille Pitchen]

The patch checks whether the Quad Enable bit is already set in the Status
Register. If so, the function exits immediately with a successful return
code. Otherwise, a message is now printed telling we're setting the
non-volatile bit.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen at atmel.com>
Reviewed-by: Jagan Teki <jagan at openedev.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index d0fc165d7d66..7ff807211e1e 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1211,6 +1211,11 @@ static int macronix_quad_enable(struct spi_nor *nor)
 	val = read_sr(nor);
 	if (val < 0)
 		return val;
+	if (val & SR_QUAD_EN_MX)
+		return 0;
+
+	/* Update the Quad Enable bit. */
+	dev_dbg(nor->dev, "setting Macronix Quad Enable (non-volatile) bit\n");
 	write_enable(nor);
 
 	write_sr(nor, val | SR_QUAD_EN_MX);
-- 
2.7.4