Revert "serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler"

commit 2cbafffbf69addd7509072f4be5917f81d238cf6 upstream.

This reverts commit f24771b62a83239f0dce816bddf0f6807f436235 as it is
reported to break the build.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202301200130.ttBiTzfO-lkp@intel.com
Fixes: f24771b62a83 ("serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler")
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Valentin Caron <valentin.caron@foss.st.com> # V3
Cc: Marek Vasut <marex@denx.de>
Cc: Johan Hovold <johan@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index c28e2f1..b8aed28 100644 (file)
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -798,9 +798,23 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
                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 uart_port *port)
        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(struct stm32_port *stm32port,
        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);