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| author |   Manfred Schlaegl <manfred.schlaegl@gmx.at> | 2015-06-20 19:25:52 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-07-23 17:37:54 -0700 |
| commit | e9b5a9825f6b02a9cf86697bcffafd3d7898f9f6 (patch) | |
| tree | 9acd5a45e426a1fe8110616d2726154edc82fa8c /drivers/tty/serial/imx.c | |
| parent | serial: imx: count tty buffer overruns (diff) | |
| download | linux-dev-e9b5a9825f6b02a9cf86697bcffafd3d7898f9f6.tar.xz linux-dev-e9b5a9825f6b02a9cf86697bcffafd3d7898f9f6.zip | |
serial: imx: reduce irq-latency after rx overflow
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.
Signed-off-by: Manfred Schlaegl <manfred.schlaegl@gmx.at>
Acked-By: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/imx.c')
| -rw-r--r-- | drivers/tty/serial/imx.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 0628fc4841ca..5b44d53f65b5 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -767,7 +767,6 @@ 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); } |