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authorMarek Vasut2023-01-12 19:04:17 +0100
committerGreg Kroah-Hartman2023-01-19 14:55:00 +0100
commitf24771b62a83239f0dce816bddf0f6807f436235 (patch)
treed50629b1c73b98b74b4165a0ff73e6dad1976286
parent4f39aca2360c82dccd2f5179d77e94aab665bea6 (diff)
serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler
Requesting an interrupt with IRQF_ONESHOT will run the primary handler in the hard-IRQ context even in the force-threaded mode. The force-threaded mode is used by PREEMPT_RT in order to avoid acquiring sleeping locks (spinlock_t) in hard-IRQ context. This combination makes it impossible and leads to "sleeping while atomic" warnings. Use one interrupt handler for both handlers (primary and secondary) and drop the IRQF_ONESHOT flag which is not needed. Fixes: e359b4411c283 ("serial: stm32: fix threaded interrupt handling") Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Valentin Caron <valentin.caron@foss.st.com> # V3 Signed-off-by: Marek Vasut <marex@denx.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230112180417.25595-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/stm32-usart.c31
1 files changed, 4 insertions, 27 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index a1490033aa16..1e24bee2b0ef 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -797,23 +797,9 @@ 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_port->throttled) {
- spin_lock_irqsave(&port->lock, flags);
+ if (stm32_usart_rx_dma_enabled(port) && !stm32_port->throttled) {
+ spin_lock(&port->lock);
size = stm32_usart_receive_chars(port, false);
uart_unlock_and_check_sysrq_irqrestore(port, flags);
if (size)
@@ -1015,10 +1001,8 @@ static int stm32_usart_startup(struct uart_port *port)
u32 val;
int ret;
- ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
- stm32_usart_threaded_interrupt,
- IRQF_ONESHOT | IRQF_NO_SUSPEND,
- name, port);
+ ret = request_irq(port->irq, stm32_usart_interrupt,
+ IRQF_NO_SUSPEND, name, port);
if (ret)
return ret;
@@ -1601,13 +1585,6 @@ 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);