[PATCH 4.19 067/125] spi: stm32: fix stm32_spi_prepare_mbr in case of odd clk_rate

Greg Kroah-Hartman
2020-09-01T16:39:18Z

From: Amelie Delaunay <amelie.delaunay@st.com>

[ Upstream commit 9cc61973bf9385b19ff5dda4a2a7e265fcba85e4 ]

Fix spi->clk_rate when it is odd to the nearest lowest even value because
minimum SPI divider is 2.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Link: https://lore.kernel.org/r/1597043558-29668-4-git-send-email-alain.volmat@st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-stm32.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index ad1e55d3d5d59..391a20b3d2fda 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -254,7 +254,8 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz)
{
u32 div, mbrdiv;

- div = DIV_ROUND_UP(spi->clk_rate, speed_hz);
+ /* Ensure spi->clk_rate is even */
+ div = DIV_ROUND_UP(spi->clk_rate & ~0x1, speed_hz);

/*
* SPI framework set xfer->speed_hz to master->max_speed_hz if
--
2.25.1