[RFC PATCH 2/2] mtd: spi-nor: Disable the flash quad mode in spi_nor_restore()

[Yicong Yang <yangyicong@xxxxxxxxxxxxx>]

If the flash's quad mode is enabled, it'll remain in the quad mode when
it's removed. If we drive the flash next time in SPI/Dual mode, then
problem occurs as the flash's quad enable bit is not cleared.

Disable the quad mode in spi_nor_restore(), the flash will leave
quad mode when remove. This will make sure the flash always enter the
correct mode when loaded.

Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
---
 drivers/mtd/spi-nor/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index d0516e8..611c0b7 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3001,6 +3001,11 @@ void spi_nor_restore(struct spi_nor *nor)
 	if (nor->addr_width == 4 && !(nor->flags & SNOR_F_4B_OPCODES) &&
 	    nor->flags & SNOR_F_BROKEN_RESET)
 		nor->params->set_4byte_addr_mode(nor, false);
+
+	/* disable quad mode */
+	if (spi_nor_get_protocol_width(nor->read_proto) == 4 ||
+	    spi_nor_get_protocol_width(nor->write_proto) == 4)
+		nor->params->quad_enable(nor, false);
 }
 EXPORT_SYMBOL_GPL(spi_nor_restore);

--
2.8.1


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