git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 2cbafffbf69addd7509072f4be5917f81d238cf6 Mon Sep 17 00:00:00 2001
   2 From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
   3 Date: Fri, 20 Jan 2023 11:16:59 +0100
   4 Subject: Revert "serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler"
   5
   6 From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
   7
   8 commit 2cbafffbf69addd7509072f4be5917f81d238cf6 upstream.
   9
  10 This reverts commit f24771b62a83239f0dce816bddf0f6807f436235 as it is
  11 reported to break the build.
  12
  13 Reported-by: kernel test robot <lkp@intel.com>
  14 Link: https://lore.kernel.org/r/202301200130.ttBiTzfO-lkp@intel.com
  15 Fixes: f24771b62a83 ("serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler")
  16 Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  17 Cc: Valentin Caron <valentin.caron@foss.st.com> # V3
  18 Cc: Marek Vasut <marex@denx.de>
  19 Cc: Johan Hovold <johan@kernel.org>
  20 Cc: stable@vger.kernel.org
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22 ---
  23  drivers/tty/serial/stm32-usart.c |   31 +++++++++++++++++++++++++++----
  24  1 file changed, 27 insertions(+), 4 deletions(-)
  25
  26 --- a/drivers/tty/serial/stm32-usart.c
  27 +++ b/drivers/tty/serial/stm32-usart.c
  28 @@ -798,9 +798,23 @@ static irqreturn_t stm32_usart_interrupt
  29                 spin_unlock(&port->lock);
  30         }
  31
  32 +       if (stm32_usart_rx_dma_enabled(port))
  33 +               return IRQ_WAKE_THREAD;
  34 +       else
  35 +               return IRQ_HANDLED;
  36 +}
  37 +
  38 +static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr)
  39 +{
  40 +       struct uart_port *port = ptr;
  41 +       struct tty_port *tport = &port->state->port;
  42 +       struct stm32_port *stm32_port = to_stm32_port(port);
  43 +       unsigned int size;
  44 +       unsigned long flags;
  45 +
  46         /* Receiver timeout irq for DMA RX */
  47 -       if (stm32_usart_rx_dma_enabled(port) && !stm32_port->throttled) {
  48 -               spin_lock(&port->lock);
  49 +       if (!stm32_port->throttled) {
  50 +               spin_lock_irqsave(&port->lock, flags);
  51                 size = stm32_usart_receive_chars(port, false);
  52                 uart_unlock_and_check_sysrq_irqrestore(port, flags);
  53                 if (size)
  54 @@ -1002,8 +1016,10 @@ static int stm32_usart_startup(struct ua
  55         u32 val;
  56         int ret;
  57
  58 -       ret = request_irq(port->irq, stm32_usart_interrupt,
  59 -                         IRQF_NO_SUSPEND, name, port);
  60 +       ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
  61 +                                  stm32_usart_threaded_interrupt,
  62 +                                  IRQF_ONESHOT | IRQF_NO_SUSPEND,
  63 +                                  name, port);
  64         if (ret)
  65                 return ret;
  66
  67 @@ -1586,6 +1602,13 @@ static int stm32_usart_of_dma_rx_probe(s
  68         struct dma_slave_config config;
  69         int ret;
  70
  71 +       /*
  72 +        * Using DMA and threaded handler for the console could lead to
  73 +        * deadlocks.
  74 +        */
  75 +       if (uart_console(port))
  76 +               return -ENODEV;
  77 +
  78         stm32port->rx_buf = dma_alloc_coherent(dev, RX_BUF_L,
  79                                                &stm32port->rx_dma_buf,
  80                                                GFP_KERNEL);