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

[platform/kernel/linux-starfive.git] / drivers / tty / serial / stm32-usart.c

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 1e24bee..a149003 100644 (file)
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -797,9 +797,23 @@ 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)
@@ -1001,8 +1015,10 @@ 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;
 
@@ -1585,6 +1601,13 @@ 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);