On Fri, Nov 20, 2020 at 09:26:53AM +0800, Tian Tao wrote: > The code has been in a irq-disabled context since it is hard IRQ. There > is no necessity to do it again. > > Signed-off-by: Tian Tao <[email protected]> > --- > drivers/tty/serial/rda-uart.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/rda-uart.c b/drivers/tty/serial/rda-uart.c > index 85366e0..d6705a0 100644 > --- a/drivers/tty/serial/rda-uart.c > +++ b/drivers/tty/serial/rda-uart.c > @@ -406,10 +406,9 @@ static void rda_uart_receive_chars(struct uart_port > *port) > static irqreturn_t rda_interrupt(int irq, void *dev_id) > { > struct uart_port *port = dev_id; > - unsigned long flags; > u32 val, irq_mask; > > - spin_lock_irqsave(&port->lock, flags); > + spin_lock(&port->lock);
This will break with forced irq threading (i.e. "threadirqs") since the console code can still end up being called from interrupt context (which can result in a deadlock). > > /* Clear IRQ cause */ > val = rda_uart_read(port, RDA_UART_IRQ_CAUSE); > @@ -426,7 +425,7 @@ static irqreturn_t rda_interrupt(int irq, void *dev_id) > rda_uart_send_chars(port); > } > > - spin_unlock_irqrestore(&port->lock, flags); > + spin_unlock(&port->lock); > > return IRQ_HANDLED; > } Johan
