[PATCH] mtd: spinand: macronix: use scratch buffer for DMA operation

[Daniel Golle <daniel@makrotopia.org>]

The mx35lf1ge4ab_get_eccsr() function uses an SPI DMA operation to
read the eccsr, hence the buffer should not be on stack. Since commit
380583227c0c7f ("spi: spi-mem: Add extra sanity checks on the op param")
the kernel emmits a warning and blocks such operations.

Use the scratch buffer to get eccsr instead of trying to directly read
into a stack-allocated variable.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/mtd/nand/spi/macronix.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/spi/macronix.c b/drivers/mtd/nand/spi/macronix.c
index dce835132a1e2..722a9738ba370 100644
--- a/drivers/mtd/nand/spi/macronix.c
+++ b/drivers/mtd/nand/spi/macronix.c
@@ -83,9 +83,10 @@ static int mx35lf1ge4ab_ecc_get_status(struct spinand_device *spinand,
 		 * in order to avoid forcing the wear-leveling layer to move
 		 * data around if it's not necessary.
 		 */
-		if (mx35lf1ge4ab_get_eccsr(spinand, &eccsr))
+		if (mx35lf1ge4ab_get_eccsr(spinand, spinand->scratchbuf))
 			return nanddev_get_ecc_conf(nand)->strength;
 
+		eccsr = *spinand->scratchbuf;
 		if (WARN_ON(eccsr > nanddev_get_ecc_conf(nand)->strength ||
 			    !eccsr))
 			return nanddev_get_ecc_conf(nand)->strength;
-- 
2.39.1