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authorValentin Caron <valentin.caron@foss.st.com>2022-01-04 19:24:44 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-01-06 15:58:46 +0100
commit2a3bcfe03725472607110507b6860d823e0deb41 (patch)
treea1b8f0d82139c3721becdfa20a3ac9a120a5e6b5 /drivers/tty
parent9a135f16d228857c5c1212a58050196883343d1e (diff)
serial: stm32: fix flow control transfer in DMA mode
If flow control is enabled, framework will call stop_tx to pause transfer and then call start_tx to resume transfer. Clear USART_CR3_DMAT bit in stop_tx ops to pause DMA transfer. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220104182445.4195-4-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/stm32-usart.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 52755a576bc2..788e002688f2 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -707,8 +707,11 @@ static void stm32_usart_stop_tx(struct uart_port *port)
{
struct stm32_port *stm32_port = to_stm32_port(port);
struct serial_rs485 *rs485conf = &port->rs485;
+ const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
stm32_usart_tx_interrupt_disable(port);
+ if (stm32_usart_tx_dma_started(stm32_port) && stm32_usart_tx_dma_enabled(stm32_port))
+ stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
if (rs485conf->flags & SER_RS485_ENABLED) {
if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {