[PATCH 6.0 0686/1073] serial: stm32: move dma_request_chan() before clk_prepare_enable()
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2022-12-28 16:20:58
Also in:
linux-patches
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Valentin Caron <redacted>
[ Upstream commit 0d114e9ff940ebad8e88267013bf96c605a6b336 ]
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 <redacted>
Signed-off-by: Valentin Caron <redacted>
Link: https://lore.kernel.org/r/20221118170602.1057863-1-valentin.caron@foss.st.com (local)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 9a875558f5ef..1f8aad186908 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c@@ -1681,22 +1681,10 @@ 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;
@@ -1710,6 +1698,17 @@ 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);
@@ -1746,19 +1745,11 @@ 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);
@@ -1768,6 +1759,14 @@ 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; }
--
2.35.1