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| author | Erwan Le Ray <erwan.leray@foss.st.com> | 2021-03-04 17:23:08 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-10 09:34:11 +0100 |
| commit | 3d82be8be6fdf38543fa3ae9c35beda4a8a8d067 (patch) | |
| tree | d8bc9cf9ab4a717db5ad7432e2a451ff5102daca | |
| parent | 3db1d52466dc11dca4e47ef12a6e6e97f846af62 (diff) | |
| download | linux-3d82be8be6fdf38543fa3ae9c35beda4a8a8d067.tar.gz linux-3d82be8be6fdf38543fa3ae9c35beda4a8a8d067.tar.bz2 linux-3d82be8be6fdf38543fa3ae9c35beda4a8a8d067.zip | |
serial: stm32: add support for "flush_buffer" ops
Add the support for "flush_buffer" ops in order to flush any write buffers,
reset any DMA state and stop any ongoing DMA transfers when the
port->state->xmit circular buffer is cleared.
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Link: https://lore.kernel.org/r/20210304162308.8984-14-erwan.leray@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/stm32-usart.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 99dfa884cbef..9db6708e3d9f 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -597,6 +597,19 @@ static void stm32_usart_start_tx(struct uart_port *port) stm32_usart_transmit_chars(port); } +/* Flush the transmit buffer. */ +static void stm32_usart_flush_buffer(struct uart_port *port) +{ + struct stm32_port *stm32_port = to_stm32_port(port); + const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + + if (stm32_port->tx_ch) { + dmaengine_terminate_async(stm32_port->tx_ch); + stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT); + stm32_port->tx_dma_busy = false; + } +} + /* Throttle the remote when input buffer is about to overflow. */ static void stm32_usart_throttle(struct uart_port *port) { @@ -992,6 +1005,7 @@ static const struct uart_ops stm32_uart_ops = { .break_ctl = stm32_usart_break_ctl, .startup = stm32_usart_startup, .shutdown = stm32_usart_shutdown, + .flush_buffer = stm32_usart_flush_buffer, .set_termios = stm32_usart_set_termios, .pm = stm32_usart_pm, .type = stm32_usart_type, |