From e6403c112f8cf573147f621533d2fa2c3fe015de Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 21 Aug 2015 20:02:55 +0200 Subject: [PATCH] serial: sh-sci: Don't call sci_rx_interrupt() on error when using DMA The error handler calls sci_rx_interrupt() to drain the receive FIFO if an error condition happens. However, if DMA is enabled on SCIFA or SCIFB, this will call disable_irq_nosync() twice. Due to this imbalance, the receive interrupt will never be re-enabled, and reception stops forever. To fix this, restrict draining the FIFO to PIO mode, and just call sci_receive_chars() directly. Inspired by a patch from Yoshihiro Shimoda . Reported-by: Yoshihiro Shimoda Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 70e16f402e31..82456fb09138 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -993,6 +993,7 @@ static irqreturn_t sci_tx_interrupt(int irq, void *ptr) static irqreturn_t sci_er_interrupt(int irq, void *ptr) { struct uart_port *port = ptr; + struct sci_port *s = to_sci_port(port); /* Handle errors */ if (port->type == PORT_SCI) { @@ -1003,7 +1004,8 @@ static irqreturn_t sci_er_interrupt(int irq, void *ptr) } } else { sci_handle_fifo_overrun(port); - sci_rx_interrupt(irq, ptr); + if (!s->chan_rx) + sci_receive_chars(ptr); } sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port)); -- 2.20.1