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path: root/drivers/spi/spi-stm32.c
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Diffstat (limited to 'drivers/spi/spi-stm32.c')
-rw-r--r--drivers/spi/spi-stm32.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index ba9743fa2326..c8e546439fff 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
@@ -298,9 +299,9 @@ static u32 stm32_spi_prepare_fthlv(struct stm32_spi *spi)
/* align packet size with data registers access */
if (spi->cur_bpw > 8)
- fthlv -= (fthlv % 2); /* multiple of 2 */
+ fthlv += (fthlv % 2) ? 1 : 0;
else
- fthlv -= (fthlv % 4); /* multiple of 4 */
+ fthlv += (fthlv % 4) ? (4 - (fthlv % 4)) : 0;
return fthlv;
}
@@ -991,6 +992,10 @@ static int stm32_spi_transfer_one(struct spi_master *master,
struct stm32_spi *spi = spi_master_get_devdata(master);
int ret;
+ /* Don't do anything on 0 bytes transfers */
+ if (transfer->len == 0)
+ return 0;
+
spi->tx_buf = transfer->tx_buf;
spi->rx_buf = transfer->rx_buf;
spi->tx_len = spi->tx_buf ? transfer->len : 0;