[PATCH 1/1] 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.

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 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index da7cd69d4857..1fd32b991eb7 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1216,6 +1216,9 @@ 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;
+
 	write_enable(nor);
 
 	write_sr(nor, val | SR_QUAD_EN_MX);
-- 
2.7.4