@@ -797,25 +797,11 @@ 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);
+ uart_unlock_and_check_sysrq(port);
if (size)
tty_flip_buffer_push(tport);
}
@@ -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);
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 --- Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Erwan Le Ray <erwan.leray@foss.st.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Valentin Caron <valentin.caron@foss.st.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-stm32@st-md-mailman.stormreply.com To: linux-serial@vger.kernel.org --- V2: - Update patch subject, was: serial: stm32: Move hard IRQ handling to threaded interrupt context - Use request_irq() instead, rename the IRQ handler function V3: - Update the commit message per suggestion from Sebastian - Add RB from Sebastian - Add Fixes tag V4: - Remove uart_console() deadlock check from stm32_usart_of_dma_rx_probe() - Use plain spin_lock()/spin_unlock() instead of the _irqsave/_irqrestore variants in IRQ handler - Add TB from Valentin V5: - Add CC stable@ - Do not move the sr variable, removes one useless hunk from the patch V6: - Replace uart_unlock_and_check_sysrq_irqrestore with uart_unlock_and_check_sysrq and drop last instance of flags --- drivers/tty/serial/stm32-usart.c | 33 +++++--------------------------- 1 file changed, 5 insertions(+), 28 deletions(-)