From: Jagan Teki <jteki@openedev.com>
Date: Tue, 15 Dec 2015 07:12:02 +0000 (+0530)
Subject: sf: Read back and check once macronix quad bit set
X-Git-Tag: v2016.03-rc1~369
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bfcdc3956d2cf4fb692b8ccbdafd56d0b4b11b2d;p=platform%2Fkernel%2Fu-boot.git

sf: Read back and check once macronix quad bit set

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@ti.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Jagan Teki <jteki@openedev.com>
---

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index b7c0da4..682d1a0 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;