linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Daney <david.daney@cavium.com>
To: linux-kernel@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>,
	Richard Purdie <rpurdie@rpsys.net>,
	Trent Piepho <xyzzy@speakeasy.org>,
	Grant Likely <grant.likely@secretlab.ca>
Subject: [PATCH] leds/of: leds-gpio.c: Use gpio_get_value_cansleep() when initializing.
Date: Tue, 30 Aug 2011 16:39:52 -0700	[thread overview]
Message-ID: <1314747592-20975-1-git-send-email-david.daney@cavium.com> (raw)

I get the following warning:

------------[ cut here ]------------
WARNING: at drivers/gpio/gpiolib.c:1559 __gpio_get_value+0x90/0x98()
Modules linked in:
Call Trace:
[<ffffffff81440950>] dump_stack+0x8/0x34
[<ffffffff81141478>] warn_slowpath_common+0x78/0xa0
[<ffffffff812f0958>] __gpio_get_value+0x90/0x98
[<ffffffff81434f04>] create_gpio_led+0xdc/0x194
[<ffffffff8143524c>] gpio_led_probe+0x290/0x36c
[<ffffffff8130e8b0>] driver_probe_device+0x78/0x1b0
[<ffffffff8130eaa8>] __driver_attach+0xc0/0xc8
[<ffffffff8130d7ac>] bus_for_each_dev+0x64/0xb0
[<ffffffff8130e130>] bus_add_driver+0x1c8/0x2a8
[<ffffffff8130f100>] driver_register+0x90/0x180
[<ffffffff81100438>] do_one_initcall+0x38/0x160

---[ end trace ee38723fbefcd65c ]---

My GPIOs are on an I2C port expander, so we must use the *_cansleep()
variant of the GPIO functions.  This is was not being done in
create_gpio_led().

We can change gpio_get_value() to gpio_get_value_cansleep() because it
is only called from the platform_driver probe function, which is a
context where we can sleep.

Only tested on my gpio_cansleep() system, but it seems safe for all
systems.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Trent Piepho <xyzzy@speakeasy.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/leds/leds-gpio.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index 3d8bc32..504cc26 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -121,7 +121,7 @@ static int __devinit create_gpio_led(const struct gpio_led *template,
 	}
 	led_dat->cdev.brightness_set = gpio_led_set;
 	if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
-		state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low;
+		state = !!gpio_get_value_cansleep(led_dat->gpio) ^ led_dat->active_low;
 	else
 		state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
 	led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
-- 
1.7.2.3


             reply	other threads:[~2011-08-30 23:40 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-30 23:39 David Daney [this message]
2011-09-09  1:35 ` [PATCH] leds/of: leds-gpio.c: Use gpio_get_value_cansleep() when initializing Andrew Morton
2011-09-09  3:54   ` Trent Piepho
2011-09-09  4:07     ` Andrew Morton
2011-09-09  5:30       ` Trent Piepho
2011-09-09  5:44         ` Andrew Morton
2011-09-09 16:15           ` David Daney
2011-09-09 17:48             ` Andrew Morton
2011-09-09 17:41           ` Trent Piepho

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=1314747592-20975-1-git-send-email-david.daney@cavium.com \
    --to=david.daney@cavium.com \
    --cc=grant.likely@secretlab.ca \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rpurdie@rpsys.net \
    --cc=xyzzy@speakeasy.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 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).