From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: Grant Likely <grant.likely@secretlab.ca>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
devicetree-discuss <devicetree-discuss@lists.ozlabs.org>,
linux-arm-kernel@lists.infradead.org,
Jeremy Kerr <jeremy.kerr@canonical.com>,
Eric Miao <eric.miao@canonical.com>,
Thomas Gleixner <tglx@linutronix.de>,
Shaju Abraham <shaju.abraham@linaro.org>
Subject: Re: Regarding hw irq to Linux irq mapping on ARM
Date: Wed, 22 Sep 2010 11:54:39 +0100 [thread overview]
Message-ID: <20100922105439.GB20986@sirena.org.uk> (raw)
In-Reply-To: <20100922105111.GA20986@sirena.org.uk>
On Wed, Sep 22, 2010 at 11:51:11AM +0100, Mark Brown wrote:
> On Wed, Sep 22, 2010 at 12:08:17AM -0300, Grant Likely wrote:
> > What's the irq handling latency on those? Glad I haven't had to deal
> > with any of them yet.
> Milisecondish, but depends on bus congestion and bus type. You need to
> schedule a thread which then does one but typically more register I/O
> operations on the device (read one or more IRQ status registers, and
> typically write back to acknowledge the interrupts as well). These tend
> for obvious reasons to be for low volume interrupts like jack detection.
Incidentally, if you want to look at an implementation the wm831x
contains an implementation of such a controller (in drivers/mfd/wm831x-irq.c)
the structure of which has been cloned for quite a few of these chips.
next prev parent reply other threads:[~2010-09-22 10:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AANLkTi=6nCJnfLB1uc0uLGOvOm0CX_R=j-8GQWTzmmep@mail.gmail.com>
[not found] ` <AANLkTi=6nCJnfLB1uc0uLGOvOm0CX_R=j-8GQWTzmmep-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-09-21 19:57 ` Regarding hw irq to Linux irq mapping on ARM Grant Likely
[not found] ` <AANLkTimp7+BLNBwZyBiPS0JgB_mno+gp8+mK=VdOd3+_-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-09-21 21:45 ` Thomas Gleixner
[not found] ` <alpine.LFD.2.00.1009212342580.2416-bi+AKbBUZKagILUCTcTcHdKyNwTtLsGr@public.gmane.org>
2010-09-22 3:08 ` Grant Likely
[not found] ` <AANLkTinrfJkK85v2epOY95YWaVyMBcxSF2xakHqsM7vh-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-09-22 5:31 ` Benjamin Herrenschmidt
2010-09-22 8:59 ` Eric Miao
2010-09-22 10:51 ` Mark Brown
2010-09-22 10:54 ` Mark Brown [this message]
2010-09-21 22:02 ` Benjamin Herrenschmidt
2010-09-22 3:06 ` Grant Likely
2010-09-22 11:00 ` Shaju Abraham
[not found] ` <AANLkTik6Nwt3O9hG971nzzEtiCLobSaWasZ4hjWCketh-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-09-22 11:52 ` Grant Likely
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