From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Jamie Lokier <jamie@shareable.org>
Cc: Valentin Longchamp <valentin.longchamp@epfl.ch>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
Wolfram Sang <w.sang@pengutronix.de>,
"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>
Subject: Re: [PATCH] serial imx.c: fix CTS trigger level lower to avoid lost chars
Date: Fri, 22 Jan 2010 16:57:19 +0000 [thread overview]
Message-ID: <20100122165719.GB18461@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20100122164713.GA21907@shareable.org>
On Fri, Jan 22, 2010 at 04:47:13PM +0000, Jamie Lokier wrote:
> Any tips on how to make the serial receive irq latency more reliable
> on ARM, with a boringly generic serial driver?
What you could do is arrange for a backtrace to be printed when
you read an overrun condition from the UART - if interrupts were
disabled by something taking a long time, and then enabled, you
should see the point where they were just enabled in the backtrace.
It could be down to another IRQF_DISABLED interrupt - in which case
you won't see it in the backtrace.
Of course, printing a backtrace will cause subsequent overruns...
next prev parent reply other threads:[~2010-01-22 16:57 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1264109163-28739-1-git-send-email-valentin.longchamp@epfl.ch>
2010-01-21 22:06 ` [PATCH] serial imx.c: fix CTS trigger level lower to avoid lost chars Wolfram Sang
2010-01-21 22:11 ` Russell King - ARM Linux
2010-01-22 10:14 ` Valentin Longchamp
2010-01-22 11:07 ` Jamie Lokier
2010-01-22 11:31 ` Russell King - ARM Linux
2010-01-22 11:49 ` Wolfram Sang
2010-01-22 16:47 ` Jamie Lokier
2010-01-22 16:47 ` Jamie Lokier
2010-01-22 16:57 ` Russell King - ARM Linux [this message]
2010-01-22 11:58 ` Wolfram Sang
2010-01-24 10:48 ` Valentin Longchamp
2010-05-05 9:47 ` Valentin Longchamp
2010-05-05 16:42 ` Greg KH
2010-05-05 23:48 ` patch serial-imx.c-fix-cts-trigger-level-lower-to-avoid-lost-chars.patch added to gregkh-2.6 tree gregkh
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