From: Valentin Caron <valentin.caron@foss.st.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@foss.st.com>,
Gerald Baeza <gerald.baeza@st.com>,
Erwan Le Ray <erwan.leray@foss.st.com>,
Valentin Caron <valentin.caron@foss.st.com>,
<linux-serial@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH 4/4] serial: stm32: correct loop for dma error handling
Date: Tue, 4 Jan 2022 19:24:45 +0100 [thread overview]
Message-ID: <20220104182445.4195-5-valentin.caron@foss.st.com> (raw)
In-Reply-To: <20220104182445.4195-1-valentin.caron@foss.st.com>
In this error handling, "transmit_chars_dma" function will call
"transmit_chars_pio" once per characters. But "transmit_chars_pio" will
continue to send characters while xmit buffer is not empty.
Remove this useless loop, one call is sufficient.
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
---
drivers/tty/serial/stm32-usart.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 788e002688f2..1f89ab0e49ac 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -477,7 +477,7 @@ static void stm32_usart_transmit_chars_dma(struct uart_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, i;
+ unsigned int count;
if (stm32_usart_tx_dma_started(stm32port)) {
if (!stm32_usart_tx_dma_enabled(stm32port))
@@ -542,8 +542,7 @@ static void stm32_usart_transmit_chars_dma(struct uart_port *port)
return;
fallback_err:
- for (i = count; i > 0; i--)
- stm32_usart_transmit_chars_pio(port);
+ stm32_usart_transmit_chars_pio(port);
}
static void stm32_usart_transmit_chars(struct uart_port *port)
--
2.17.1
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prev parent reply other threads:[~2022-01-04 18:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-04 18:24 [PATCH 0/4] Add improvements for STM32 USART DMA TX Valentin Caron
2022-01-04 18:24 ` [PATCH 1/4] serial: stm32: move tx dma terminate DMA to shutdown Valentin Caron
2022-01-04 18:24 ` [PATCH 2/4] serial: stm32: rework TX DMA state condition Valentin Caron
2022-01-04 18:24 ` [PATCH 3/4] serial: stm32: fix flow control transfer in DMA mode Valentin Caron
2022-01-04 18:24 ` Valentin Caron [this message]
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