From: Valentin Caron <valentin.caron@foss.st.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Valentin Caron" <valentin.caron@foss.st.com>,
"Jiri Slaby" <jirislaby@kernel.org>,
"Alexandre Torgue" <alexandre.torgue@foss.st.com>,
"Erwan Le Ray" <erwan.leray@foss.st.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
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] serial: stm32: move dma_request_chan() before clk_prepare_enable()
Date: Fri, 18 Nov 2022 18:06:02 +0100 [thread overview]
Message-ID: <20221118170602.1057863-1-valentin.caron@foss.st.com> (raw)
If dma_request_chan() returns a PROBE_DEFER error, clk_disable_unprepare()
will be called and USART clock will be disabled. But early console can be
still active on the same USART.
While moving dma_request_chan() before clk_prepare_enable(), the clock
won't be taken in case of a DMA PROBE_DEFER error, and so it doesn't need
to be disabled. Then USART is still clocked for early console.
Fixes: a7770a4bfcf4 ("serial: stm32: defer probe for dma devices")
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
---
drivers/tty/serial/stm32-usart.c | 47 ++++++++++++++++----------------
1 file changed, 23 insertions(+), 24 deletions(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 24def72b2565..a1490033aa16 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -1680,22 +1680,10 @@ static int stm32_usart_serial_probe(struct platform_device *pdev)
if (!stm32port->info)
return -EINVAL;
- ret = stm32_usart_init_port(stm32port, pdev);
- if (ret)
- return ret;
-
- if (stm32port->wakeup_src) {
- device_set_wakeup_capable(&pdev->dev, true);
- ret = dev_pm_set_wake_irq(&pdev->dev, stm32port->port.irq);
- if (ret)
- goto err_deinit_port;
- }
-
stm32port->rx_ch = dma_request_chan(&pdev->dev, "rx");
- if (PTR_ERR(stm32port->rx_ch) == -EPROBE_DEFER) {
- ret = -EPROBE_DEFER;
- goto err_wakeirq;
- }
+ if (PTR_ERR(stm32port->rx_ch) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
/* Fall back in interrupt mode for any non-deferral error */
if (IS_ERR(stm32port->rx_ch))
stm32port->rx_ch = NULL;
@@ -1709,6 +1697,17 @@ static int stm32_usart_serial_probe(struct platform_device *pdev)
if (IS_ERR(stm32port->tx_ch))
stm32port->tx_ch = NULL;
+ ret = stm32_usart_init_port(stm32port, pdev);
+ if (ret)
+ goto err_dma_tx;
+
+ if (stm32port->wakeup_src) {
+ device_set_wakeup_capable(&pdev->dev, true);
+ ret = dev_pm_set_wake_irq(&pdev->dev, stm32port->port.irq);
+ if (ret)
+ goto err_deinit_port;
+ }
+
if (stm32port->rx_ch && stm32_usart_of_dma_rx_probe(stm32port, pdev)) {
/* Fall back in interrupt mode */
dma_release_channel(stm32port->rx_ch);
@@ -1745,19 +1744,11 @@ static int stm32_usart_serial_probe(struct platform_device *pdev)
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
- if (stm32port->tx_ch) {
+ if (stm32port->tx_ch)
stm32_usart_of_dma_tx_remove(stm32port, pdev);
- dma_release_channel(stm32port->tx_ch);
- }
-
if (stm32port->rx_ch)
stm32_usart_of_dma_rx_remove(stm32port, pdev);
-err_dma_rx:
- if (stm32port->rx_ch)
- dma_release_channel(stm32port->rx_ch);
-
-err_wakeirq:
if (stm32port->wakeup_src)
dev_pm_clear_wake_irq(&pdev->dev);
@@ -1767,6 +1758,14 @@ static int stm32_usart_serial_probe(struct platform_device *pdev)
stm32_usart_deinit_port(stm32port);
+err_dma_tx:
+ if (stm32port->tx_ch)
+ dma_release_channel(stm32port->tx_ch);
+
+err_dma_rx:
+ if (stm32port->rx_ch)
+ dma_release_channel(stm32port->rx_ch);
+
return ret;
}
--
2.25.1
reply other threads:[~2022-11-18 17:06 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20221118170602.1057863-1-valentin.caron@foss.st.com \
--to=valentin.caron@foss.st.com \
--cc=alexandre.torgue@foss.st.com \
--cc=erwan.leray@foss.st.com \
--cc=gregkh@linuxfoundation.org \
--cc=jirislaby@kernel.org \
--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=u.kleine-koenig@pengutronix.de \
/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).