From: Manfred Schlaegl <manfred.schlaegl@xxxxxx>
commit e9b5a9825f6b02a9cf86697bcffafd3d7898f9f6 upstream.
To prevent problems with interrupt latency, and due to the fact, that
the error will be counted anyway (icount.overrun), the dev_err is simply
removed.
Background:
If an rx-fifo overflow occurs a dev_err message was called in interrupt
context. Since dev_err messages are written to console in a synchronous way
(unbuffered), and console may be a serial terminal, this leads to a
highly increased interrupt-latency (several milliseconds).
As a result of the high latency more rx-fifo overflows will happen, and
therefore a feedback loop of errors is created.
Cc: <stable@xxxxxxxxxxxxxxx> # 4.1.x
Signed-off-by: Manfred Schlaegl <manfred.schlaegl@xxxxxx>
Acked-By: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx>
---
drivers/tty/serial/imx.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 01aa52f..60ace71 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -766,7 +766,6 @@ static irqreturn_t imx_int(int irq, void *dev_id)
writel(USR1_AWAKE, sport->port.membase + USR1);
if (sts2 & USR2_ORE) {
- dev_err(sport->port.dev, "Rx FIFO overrun\n");
sport->port.icount.overrun++;
writel(USR2_ORE, sport->port.membase + USR2);
}
--
1.9.1
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