[U-Boot] [PATCH v3 3/4] sf: Read back and check once macronix quad bit set

[Jagan Teki]

One macronix quad bit set using SR, it's good to
read back and check the written bit and also if
it's already been set check for the bit and return.

Cc: Vignesh R <vigneshr at ti.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Bin Meng <bmeng.cn at gmail.com>
Tested-by: Mugunthan V N <mugunthanvnm at ti.com>
Signed-off-by: Jagan Teki <jteki at openedev.com>
---
Changes for v3:
	- Fixed if statement for 'quad bit not clear' 
Changes for v2:
	- none

 drivers/mtd/spi/spi_flash.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index c3deda5..56217c2 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -840,12 +840,18 @@ static int macronix_quad_enable(struct spi_flash *flash)
 	if (ret < 0)
 		return ret;
 
-	if (qeb_status & STATUS_QEB_MXIC) {
-		debug("SF: mxic: QEB is already set\n");
-	} else {
-		ret = write_sr(flash, STATUS_QEB_MXIC);
-		if (ret < 0)
-			return ret;
+	if (qeb_status & STATUS_QEB_MXIC)
+		return 0;
+
+	ret = write_sr(flash, STATUS_QEB_MXIC);
+	if (ret < 0)
+		return ret;
+
+	/* read SR and check it */
+	ret = read_sr(flash, &qeb_status);
+	if (!(ret >= 0 && (qeb_status & STATUS_QEB_MXIC))) {
+		printf("SF: Macronix SR Quad bit not clear\n");
+		return -EINVAL;
 	}
 
 	return ret;
-- 
1.9.1