| Message ID | 1612523342-10466-2-git-send-email-alain.volmat@foss.st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | spi: stm32: fix and enhancements for spi-stm32 | expand |
On Fri, Feb 05, 2021 at 12:08:55PM +0100, Alain Volmat wrote: > On 0 byte transfer request, return straight from the > xfer function after finalizing the transfer. > + if (transfer->len == 0) { > + spi_finalize_current_transfer(master); > + return 0; The driver only needs to finalize the transfer if it returned a value greater than 0, returning 0 indicates that the transfer is already done.
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;
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(+)