Commit 00bc5e8f authored by Valentin Caron's avatar Valentin Caron Committed by Greg Kroah-Hartman
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serial: stm32: use DMAT as a configuration bit 



DMAT is a configuration bit so it should be set at the startup of uart
port and not when a DMA transfer begins.

This patch move set of DMAT into set_termios and remove DMAT reset except
in shutdown.

Signed-off-by: default avatarValentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20230808161906.178996-3-valentin.caron@foss.st.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent db89728a

drivers/tty/serial/stm32-usart.c

+3 −5
Original line number Diff line number Diff line
@@ -510,10 +510,8 @@ static void stm32_usart_tx_dma_complete(void *arg) 
{

	struct uart_port *port = arg;

	struct stm32_port *stm32port = to_stm32_port(port);

	const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;

	unsigned long flags;



	stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);

	stm32_usart_tx_dma_terminate(stm32port);



	/* Let's see if we have pending data to send */
@@ -602,7 +600,6 @@ static void stm32_usart_transmit_chars_pio(struct uart_port *port) 
static void stm32_usart_transmit_chars_dma(struct uart_port *port)

{

	struct stm32_port *stm32port = to_stm32_port(port);

	const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;

	struct circ_buf *xmit = &port->state->xmit;

	struct dma_async_tx_descriptor *desc = NULL;

	unsigned int count;
@@ -667,8 +664,6 @@ static void stm32_usart_transmit_chars_dma(struct uart_port *port) 
	/* Issue pending DMA TX requests */

	dma_async_issue_pending(stm32port->tx_ch);



	stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAT);



	uart_xmit_advance(port, count);



	return;
@@ -1270,6 +1265,9 @@ static void stm32_usart_set_termios(struct uart_port *port, 
		cr3 |= USART_CR3_DDRE;

	}



	if (stm32_port->tx_ch)

		cr3 |= USART_CR3_DMAT;



	if (rs485conf->flags & SER_RS485_ENABLED) {

		stm32_usart_config_reg_rs485(&cr1, &cr3,

					     rs485conf->delay_rts_before_send,