From 00bc5e8fc91743753a3ac9de1e9567e844ae3967 Mon Sep 17 00:00:00 2001 From: Valentin Caron Date: Tue, 8 Aug 2023 18:19:02 +0200 Subject: [PATCH] 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: Valentin Caron Link: https://lore.kernel.org/r/20230808161906.178996-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/stm32-usart.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 2f9672b..a1585aa 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -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, -- 2.7.4