spi: stm32: fix error check on mbr being -ve

The error check of mbr < 0 is always false because mbr is a u32. Make
mbt an int so that a -ve error return from stm32_spi_prepare_mbr can be
detected.

Detected by CoverityScan, CID#1446586 ("Unsigned compared against 0")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 0553f61ab3b7..305ecd5334fc 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -857,7 +857,7 @@ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
         }
 
         if (spi->cur_speed != transfer->speed_hz) {
-                u32 mbr;
+                int mbr;
 
                 /* Update spi->cur_speed with real clock speed */
                 mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz);
@@ -869,7 +869,7 @@ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
                 transfer->speed_hz = spi->cur_speed;
 
                 cfg1_clrb |= SPI_CFG1_MBR;
-                cfg1_setb |= (mbr << SPI_CFG1_MBR_SHIFT) & SPI_CFG1_MBR;
+                cfg1_setb |= ((u32)mbr << SPI_CFG1_MBR_SHIFT) & SPI_CFG1_MBR;
         }
 
         if (cfg1_clrb || cfg1_setb)