serial: stm32: fix tx dma completion, release channel

[ Upstream commit fb4f2e04ac13e7c400e6b86afbbd314a5a2a7e8d ]

This patch add a proper release of dma channels when completing dma tx.

Fixes: 3489187204eb ("serial: stm32: adding dma support")
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Link: https://lore.kernel.org/r/20210304162308.8984-9-erwan.leray@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index a381ee52168a0e0dfe63698c5348e2f029898cf4..74046ae3a41210f39f75e6c2fd11bb61ea9a0b1c 100644 (file)
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -292,6 +292,7 @@ static void stm32_usart_tx_dma_complete(void *arg)
        struct stm32_port *stm32port = to_stm32_port(port);
        const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
 
+       dmaengine_terminate_async(stm32port->tx_ch);
        stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
        stm32port->tx_dma_busy = false;