[U-Boot] [PATCH v3 2/4] sf: Read back and check once spansion quad bit set

[Jagan Teki]

One spansion quad bit set using CR, 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>
Cc: Michal Simek <michal.simek at xilinx.com>
Cc: Siva Durga Prasad Paladugu <sivadur at xilinx.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 30058d0..c3deda5 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -862,12 +862,18 @@ static int spansion_quad_enable(struct spi_flash *flash)
 	if (ret < 0)
 		return ret;
 
-	if (qeb_status & STATUS_QEB_WINSPAN) {
-		debug("SF: winspan: QEB is already set\n");
-	} else {
-		ret = write_cr(flash, STATUS_QEB_WINSPAN);
-		if (ret < 0)
-			return ret;
+	if (qeb_status & STATUS_QEB_WINSPAN)
+		return 0;
+
+	ret = write_cr(flash, STATUS_QEB_WINSPAN);
+	if (ret < 0)
+		return ret;
+
+	/* read CR and check it */
+	ret = read_cr(flash, &qeb_status);
+	if (!(ret >= 0 && (qeb_status & STATUS_QEB_WINSPAN))) {
+		printf("SF: Spansion CR Quad bit not clear\n");
+		return -EINVAL;
 	}
 
 	return ret;
-- 
1.9.1