From: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
To: Jonathan Bell <jonathan-FnsA7b+Nu9XbIbC87yuRow@public.gmane.org>,
Linus Walleij
<linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
Lee Jones <lee-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: linux-gpio <linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
linux-rpi-kernel
<linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>
Subject: Re: [PATCH] pinctrl: bcm2835: Clear the event latch register when disabling interrupts
Date: Fri, 10 Jul 2015 22:15:40 -0600 [thread overview]
Message-ID: <55A0986C.1030905@wwwdotorg.org> (raw)
In-Reply-To: <55927F0B.80602-FnsA7b+Nu9XbIbC87yuRow@public.gmane.org>
On 06/30/2015 05:35 AM, Jonathan Bell wrote:
> It's possible to hit a race condition if interrupts are generated on a GPIO
> pin when the IRQ line in question is being disabled.
>
> If the interrupt is freed, bcm2835_gpio_irq_disable() is called which
> disables the event generation sources (edge, level). If an event occurred
> between the last disabling of hard IRQs and the write to the event
> source registers, a bit would be set in the GPIO event detect register
> (GPEDSn) which goes unacknowledged by bcm2835_gpio_irq_handler()
> so Linux complains loudly.
>
> There is no per-GPIO mask register, so when disabling GPIO interrupts
> write 1 to the relevant bit in GPEDSn to clear out any stale events.
Acked-by: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
(Sorry for the slow response; I was on vacation)
next prev parent reply other threads:[~2015-07-11 4:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-30 11:35 [PATCH] pinctrl: bcm2835: Clear the event latch register when disabling interrupts Jonathan Bell
[not found] ` <55927F0B.80602-FnsA7b+Nu9XbIbC87yuRow@public.gmane.org>
2015-07-11 4:15 ` Stephen Warren [this message]
2015-07-16 13:33 ` Linus Walleij
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=55A0986C.1030905@wwwdotorg.org \
--to=swarren-3lzwwm7+weoh9zmkesr00q@public.gmane.org \
--cc=jonathan-FnsA7b+Nu9XbIbC87yuRow@public.gmane.org \
--cc=lee-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
--cc=linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
--cc=linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.