[PATCH 1/8] spi: stm32: properly handle 0 byte transfer
From: Alain Volmat <alain.volmat@foss.st.com>
Date: 2021-02-05 11:21:21
Also in:
linux-arm-kernel, lkml
Subsystem:
spi subsystem, st stm32 spi driver, the rest · Maintainers:
Mark Brown, Alain Volmat, Linus Torvalds
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 <alain.volmat@foss.st.com>
---
drivers/spi/spi-stm32.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index db3e305d9ec4..137213633e6d 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c@@ -1657,6 +1657,12 @@ 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) { + spi_finalize_current_transfer(master); + 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