From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Marc Zyngier <marc.zyngier@arm.com>,
Brendan Higgins <brendanhiggins@google.com>,
wsa@the-dreams.de, robh+dt@kernel.org, mark.rutland@arm.com,
tglx@linutronix.de, jason@lakedaemon.net, joel@jms.id.au,
vz@mleia.com, mouse@mayc.ru, clg@kaod.org
Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org
Subject: Re: [PATCH v6 2/5] irqchip/aspeed-i2c-ic: Add I2C IRQ controller for Aspeed
Date: Tue, 28 Mar 2017 20:12:55 +1100 [thread overview]
Message-ID: <1490692375.3177.119.camel@kernel.crashing.org> (raw)
In-Reply-To: <49a13bbc-aec3-a349-4323-3c8d2728c62f@arm.com>
On Tue, 2017-03-28 at 09:32 +0100, Marc Zyngier wrote:
> I'm a bit concerned by this. It means that you can't even mask an
> interrupt. Is that really what you intend to do? Or all that the HW can
> do? If you cannot mask an interrupt, you're at the mercy of a screaming
> device...
This is not really an interrupt controller. It's a "summary" register
that reflects the state of the 14 i2c controller interrupts.
This approach does have the advantage of providing separate counters in
/proc/interrupts which is rather nice, but it does have overhead. On
those shittly little ARMv9 400Mhz cores it can be significant.
I would personally have some kind of trick to register a single
interrupt handler that calls directly the handlers of the respective
i2c busses via a simple indirection for speed, maybe adding my custom
sysfs or debugfs statistics. But that's just me trying to suck the last
cycle out of the bloody thing ;-)
Cheers,
Ben.
next prev parent reply other threads:[~2017-03-28 9:12 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-28 5:12 [PATCH v6 0/5] i2c: aspeed: added driver for Aspeed I2C Brendan Higgins
2017-03-28 5:12 ` [PATCH v6 1/5] irqchip/aspeed-i2c-ic: binding docs for Aspeed I2C Interrupt Controller Brendan Higgins
2017-03-28 8:49 ` Benjamin Herrenschmidt
2017-03-29 10:34 ` Brendan Higgins
2017-03-29 12:11 ` Benjamin Herrenschmidt
2017-03-29 20:51 ` Brendan Higgins
2017-03-29 21:17 ` Benjamin Herrenschmidt
[not found] ` <20170328051226.21677-2-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-04-03 14:16 ` Rob Herring
2017-03-28 5:12 ` [PATCH v6 3/5] i2c: aspeed: added documentation for Aspeed I2C driver Brendan Higgins
[not found] ` <20170328051226.21677-4-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-03-28 8:54 ` Benjamin Herrenschmidt
[not found] ` <1490691283.3177.112.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2017-03-29 10:25 ` Brendan Higgins
2017-04-03 14:22 ` Rob Herring
2017-04-03 14:24 ` Rob Herring
2017-03-28 5:12 ` [PATCH v6 5/5] i2c: aspeed: added slave support " Brendan Higgins
[not found] ` <20170328051226.21677-1-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-03-28 5:12 ` [PATCH v6 2/5] irqchip/aspeed-i2c-ic: Add I2C IRQ controller for Aspeed Brendan Higgins
[not found] ` <20170328051226.21677-3-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-03-28 8:32 ` Marc Zyngier
2017-03-28 9:12 ` Benjamin Herrenschmidt [this message]
[not found] ` <1490692375.3177.119.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2017-03-28 9:40 ` Marc Zyngier
[not found] ` <91936f1a-0a0d-4091-b981-976503a6f7cd-5wv7dgnIgG8@public.gmane.org>
2017-03-28 20:50 ` Benjamin Herrenschmidt
[not found] ` <1490734216.3177.140.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2017-03-29 9:59 ` Brendan Higgins
2017-03-29 10:55 ` Marc Zyngier
2017-03-28 8:52 ` Benjamin Herrenschmidt
2017-03-29 10:58 ` Joel Stanley
2017-03-29 20:16 ` Brendan Higgins
2017-03-28 5:12 ` [PATCH v6 4/5] i2c: aspeed: added driver for Aspeed I2C Brendan Higgins
2017-03-28 8:57 ` Benjamin Herrenschmidt
2017-03-28 9:09 ` Benjamin Herrenschmidt
2017-03-29 10:23 ` Brendan Higgins
2017-03-31 0:33 ` Joel Stanley
[not found] ` <20170328051226.21677-5-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-03-31 7:33 ` Benjamin Herrenschmidt
[not found] ` <1490945610.3177.229.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2017-04-24 18:56 ` Brendan Higgins
2017-04-25 2:19 ` Benjamin Herrenschmidt
[not found] ` <1493086747.25766.264.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2017-04-25 8:32 ` Brendan Higgins
2017-04-25 8:50 ` Ryan Chen
2017-04-25 9:34 ` Benjamin Herrenschmidt
[not found] ` <1493112875.25766.268.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2017-04-25 9:47 ` Ryan Chen
2017-04-25 19:50 ` Brendan Higgins
[not found] ` <CAFd5g45htFgr5oHbB9W_nyyMfm5J7BCKUuP73RxKhNW3LkWtyw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-04-26 0:52 ` Ryan Chen
2017-03-31 0:01 ` [PATCH v6 0/5] " Andrew Jeffery
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1490692375.3177.119.camel@kernel.crashing.org \
--to=benh@kernel.crashing.org \
--cc=brendanhiggins@google.com \
--cc=clg@kaod.org \
--cc=devicetree@vger.kernel.org \
--cc=jason@lakedaemon.net \
--cc=joel@jms.id.au \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=marc.zyngier@arm.com \
--cc=mark.rutland@arm.com \
--cc=mouse@mayc.ru \
--cc=openbmc@lists.ozlabs.org \
--cc=robh+dt@kernel.org \
--cc=tglx@linutronix.de \
--cc=vz@mleia.com \
--cc=wsa@the-dreams.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).