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authorAlain Volmat <alain.volmat@foss.st.com>2021-02-05 19:59:25 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-03-03 18:22:47 +0100
commit7ca753238809a6766d27c72fb3aa329b96c31a33 (patch)
tree7de1353c92f9d533c6b34f919754fc99eac55c60 /drivers/spi
parent5873b3a5fde23dd95d8b4a3f8306cf6643d30060 (diff)
spi: stm32: properly handle 0 byte transfer
[ Upstream commit 2269f5a8b1a7b38651d62676b98182828f29d11a ] 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> Link: https://lore.kernel.org/r/1612551572-495-2-git-send-email-alain.volmat@foss.st.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-stm32.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index d91980354051..c8e546439fff 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -992,6 +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;