From: Tudor Ambarus <tudor.ambarus@microchip.com>
Date: Tue, 3 Dec 2019 14:50:01 +0000
Subject: mtd: spi-nor: Fix the writing of the Status Register on micron
 flashes
Git-commit: 82de6a6fb67e16a30ec2f586b1f6976c2d7b4b62
Patch-mainline: v5.5-rc6
References: jsc#SLE-14214 jsc#SLE-16606

Micron flashes do not support 16 bit writes on the Status Register.
According to micron datasheets, when using the Write Status Register
(01h) command, the chip select should be driven LOW and held LOW until
the eighth bit of the last data byte has been latched in, after which
it must be driven HIGH. If CS is not driven HIGH, the command is not
executed, flag status register error bits are not set, and the write enable
latch remains set to 1. This fixes the lock operations on micron flashes.

Reported-by: John Garry <john.garry@huawei.com>
Fixes: 39d1e3340c73 ("mtd: spi-nor: Fix clearing of QE bit on lock()/unlock()")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Tested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index f4afe123e9dc..aeb3ad2dbfb8 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -4596,6 +4596,7 @@ static void sst_set_default_init(struct spi_nor *nor)
 static void st_micron_set_default_init(struct spi_nor *nor)
 {
 	nor->flags |= SNOR_F_HAS_LOCK;
+	nor->flags &= ~SNOR_F_HAS_16BIT_SR;
 	nor->params.quad_enable = NULL;
 	nor->params.set_4byte = st_micron_set_4byte;
 }
-- 
2.28.0