From: Erwan Le Ray <erwan.leray@foss.st.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: <linux-serial@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
Erwan Le Ray <erwan.leray@foss.st.com>,
Fabrice Gasnier <fabrice.gasnier@foss.st.com>,
Valentin Caron <valentin.caron@foss.st.com>
Subject: [PATCH v2 03/13] serial: stm32: fix incorrect characters on console
Date: Thu, 4 Mar 2021 17:22:58 +0100 [thread overview]
Message-ID: <20210304162308.8984-4-erwan.leray@foss.st.com> (raw)
In-Reply-To: <20210304162308.8984-1-erwan.leray@foss.st.com>
Incorrect characters are observed on console during boot. This issue occurs
when init/main.c is modifying termios settings to open /dev/console on the
rootfs.
This patch adds a waiting loop in set_termios to wait for TX shift register
empty (and TX FIFO if any) before stopping serial port.
Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver")
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index c6ca8f964c69..eae54b8cf5e2 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -738,8 +738,9 @@ static void stm32_usart_set_termios(struct uart_port *port,
unsigned int baud, bits;
u32 usartdiv, mantissa, fraction, oversampling;
tcflag_t cflag = termios->c_cflag;
- u32 cr1, cr2, cr3;
+ u32 cr1, cr2, cr3, isr;
unsigned long flags;
+ int ret;
if (!stm32_port->hw_flow_control)
cflag &= ~CRTSCTS;
@@ -748,6 +749,15 @@ static void stm32_usart_set_termios(struct uart_port *port,
spin_lock_irqsave(&port->lock, flags);
+ ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
+ isr,
+ (isr & USART_SR_TC),
+ 10, 100000);
+
+ /* Send the TC error message only when ISR_TC is not set. */
+ if (ret)
+ dev_err(port->dev, "Transmission is not complete\n");
+
/* Stop serial port and reset value */
writel_relaxed(0, port->membase + ofs->cr1);
--
2.17.1
next prev parent reply other threads:[~2021-03-04 16:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-04 16:22 [PATCH v2 00/13] stm32 usart various fixes Erwan Le Ray
2021-03-04 16:22 ` [PATCH v2 01/13] serial: stm32: fix probe and remove order for dma Erwan Le Ray
2021-03-04 16:22 ` [PATCH v2 02/13] serial: stm32: fix startup by enabling usart for reception Erwan Le Ray
2021-03-04 16:22 ` Erwan Le Ray [this message]
2021-03-04 16:22 ` [PATCH v2 04/13] serial: stm32: fix TX and RX FIFO thresholds Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 05/13] serial: stm32: fix a deadlock condition with wakeup event Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 06/13] serial: stm32: fix wake-up flag handling Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 07/13] serial: stm32: fix a deadlock in set_termios Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 08/13] serial: stm32: fix tx dma completion, release channel Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 09/13] serial: stm32: call stm32_transmit_chars locked Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 10/13] serial: stm32: fix FIFO flush in startup and set_termios Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 11/13] serial: stm32: add FIFO flush when port is closed Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 12/13] serial: stm32: fix tx_empty condition Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 13/13] serial: stm32: add support for "flush_buffer" ops Erwan Le Ray
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210304162308.8984-4-erwan.leray@foss.st.com \
--to=erwan.leray@foss.st.com \
--cc=alexandre.torgue@foss.st.com \
--cc=fabrice.gasnier@foss.st.com \
--cc=gregkh@linuxfoundation.org \
--cc=jslaby@suse.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=linux-stm32@st-md-mailman.stormreply.com \
--cc=mcoquelin.stm32@gmail.com \
--cc=valentin.caron@foss.st.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).