[PATCH AUTOSEL 5.8 15/63] spi: stm32: fix stm32_spi_prepare_mbr in case of odd clk_rate

Sasha Levin sashal at kernel.org
Mon Aug 24 12:34:15 EDT 2020


From: Amelie Delaunay <amelie.delaunay at 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 at st.com>
Signed-off-by: Alain Volmat <alain.volmat at st.com>
Link: https://lore.kernel.org/r/1597043558-29668-4-git-send-email-alain.volmat@st.com
Signed-off-by: Mark Brown <broonie at kernel.org>
Signed-off-by: Sasha Levin <sashal at 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 e5450233f3f8b..571dea72bf7e6 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -441,7 +441,8 @@ 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




More information about the linux-arm-kernel mailing list