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From: marex@denx.de (Marek Vasut)
To: linux-arm-kernel@lists.infradead.org
Subject: Improve timer Resolution on imx28
Date: Fri, 21 Dec 2012 15:52:17 +0100	[thread overview]
Message-ID: <201212211552.17744.marex@denx.de> (raw)
In-Reply-To: <1356098776-10498-1-git-send-email-torbenh@linutronix.de>

Dear Torben Hohn,

> Hi,
> 
> this Series increases the timer frequency and decreases min_delta_ns.
> I saw pretty high max latencies with cyclictest: ~600us.
> 
> The cause was the min_delta_ns value of 0xf 32kHz clockcycles.
> But with the 32kHz Clock, the period is still around 30us.
> So we just increase the clock freqeuncy driving the timers
> here.

Thanks for the set. Just a really quick question -- won't this under no 
circumstance cause interrupt storm?

Best regards,
Marek Vasut

WARNING: multiple messages have this Message-ID (diff)
From: Marek Vasut <marex@denx.de>
To: Torben Hohn <torbenh@linutronix.de>
Cc: Shawn Guo <shawn.guo@linaro.org>,
	Russell King <linux@arm.linux.org.uk>,
	Mike Turquette <mturquette@linaro.org>,
	Dong Aisheng <dong.aisheng@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Fabio Estevam <fabio.estevam@freescale.com>
Subject: Re: Improve timer Resolution on imx28
Date: Fri, 21 Dec 2012 15:52:17 +0100	[thread overview]
Message-ID: <201212211552.17744.marex@denx.de> (raw)
In-Reply-To: <1356098776-10498-1-git-send-email-torbenh@linutronix.de>

Dear Torben Hohn,

> Hi,
> 
> this Series increases the timer frequency and decreases min_delta_ns.
> I saw pretty high max latencies with cyclictest: ~600us.
> 
> The cause was the min_delta_ns value of 0xf 32kHz clockcycles.
> But with the 32kHz Clock, the period is still around 30us.
> So we just increase the clock freqeuncy driving the timers
> here.

Thanks for the set. Just a really quick question -- won't this under no 
circumstance cause interrupt storm?

Best regards,
Marek Vasut

  parent reply	other threads:[~2012-12-21 14:52 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-21 14:06 Improve timer Resolution on imx28 Torben Hohn
2012-12-21 14:06 ` Torben Hohn
2012-12-21 14:06 ` [PATCH 1/2] mxs timer: use ahbx bus clock to drive the timers on timrotv2 Torben Hohn
2012-12-21 14:06   ` Torben Hohn
2012-12-25 14:10   ` Shawn Guo
2012-12-25 14:10     ` Shawn Guo
2012-12-21 14:06 ` [PATCH 2/2] mxs timer: decrease mxs_clockevent_device.min_delta_ns to 2 clock cycles Torben Hohn
2012-12-21 14:06   ` Torben Hohn
2012-12-21 14:52 ` Marek Vasut [this message]
2012-12-21 14:52   ` Improve timer Resolution on imx28 Marek Vasut

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