2021-02-05 19:06:37

by Alain Volmat

[permalink] [raw]
Subject: [PATCH v2 1/8] spi: stm32: properly handle 0 byte transfer

On 0 byte transfer request, return straight from the
xfer function after finalizing the transfer.

Fixes: dcbe0d84dfa5 ("spi: add driver for STM32 SPI controller")
Signed-off-by: Alain Volmat <[email protected]>
---
v2: remove useless spi_finalize_current_transfer

drivers/spi/spi-stm32.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index db3e305d9ec4..6cdecd1c5ec7 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1657,6 +1657,10 @@ 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;
--
2.17.1