From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> commit 2cbafffbf69addd7509072f4be5917f81d238cf6 upstream. This reverts commit f24771b62a83239f0dce816bddf0f6807f436235 as it is reported to break the build. Reported-by: kernel test robot <lkp@xxxxxxxxx> Link: https://lore.kernel.org/r/202301200130.ttBiTzfO-lkp@xxxxxxxxx Fixes: f24771b62a83 ("serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler") Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Cc: Valentin Caron <valentin.caron@xxxxxxxxxxx> # V3 Cc: Marek Vasut <marex@xxxxxxx> Cc: Johan Hovold <johan@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/stm32-usart.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -798,9 +798,23 @@ static irqreturn_t stm32_usart_interrupt spin_unlock(&port->lock); } + if (stm32_usart_rx_dma_enabled(port)) + return IRQ_WAKE_THREAD; + else + return IRQ_HANDLED; +} + +static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + struct tty_port *tport = &port->state->port; + struct stm32_port *stm32_port = to_stm32_port(port); + unsigned int size; + unsigned long flags; + /* Receiver timeout irq for DMA RX */ - if (stm32_usart_rx_dma_enabled(port) && !stm32_port->throttled) { - spin_lock(&port->lock); + if (!stm32_port->throttled) { + spin_lock_irqsave(&port->lock, flags); size = stm32_usart_receive_chars(port, false); uart_unlock_and_check_sysrq_irqrestore(port, flags); if (size) @@ -1002,8 +1016,10 @@ static int stm32_usart_startup(struct ua u32 val; int ret; - ret = request_irq(port->irq, stm32_usart_interrupt, - IRQF_NO_SUSPEND, name, port); + ret = request_threaded_irq(port->irq, stm32_usart_interrupt, + stm32_usart_threaded_interrupt, + IRQF_ONESHOT | IRQF_NO_SUSPEND, + name, port); if (ret) return ret; @@ -1586,6 +1602,13 @@ static int stm32_usart_of_dma_rx_probe(s struct dma_slave_config config; int ret; + /* + * Using DMA and threaded handler for the console could lead to + * deadlocks. + */ + if (uart_console(port)) + return -ENODEV; + stm32port->rx_buf = dma_alloc_coherent(dev, RX_BUF_L, &stm32port->rx_dma_buf, GFP_KERNEL);
