From: Tony Lindgren <tony@atomide.com>
To: Lee Jones <lee.jones@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org,
linux-omap@vger.kernel.org, Bryan Wu <cooloney@gmail.com>,
Jingoo Han <jg1.han@samsung.com>,
Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>,
Tomi Valkeinen <tomi.valkeinen@ti.com>
Subject: [PATCH] backlight: gpio-backlight: Fix warning when the GPIO is on a I2C chip
Date: Thu, 8 May 2014 18:24:55 -0700 [thread overview]
Message-ID: <20140509012454.GL2198@atomide.com> (raw)
If the GPIO for the backlight is on an I2C chip, we currently
get nasty warnings like this during the boot:
WARNING: CPU: 0 PID: 6 at drivers/gpio/gpiolib.c:2364 gpiod_set_raw_value+0x40/0x4c()
Modules linked in:
CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 3.15.0-rc4-12393-gcde9f4e #400
Workqueue: deferwq deferred_probe_work_func
[<c0014cbc>] (unwind_backtrace) from [<c001191c>] (show_stack+0x10/0x14)
[<c001191c>] (show_stack) from [<c0566ae0>] (dump_stack+0x80/0x9c)
[<c0566ae0>] (dump_stack) from [<c003f61c>] (warn_slowpath_common+0x68/0x8c)
[<c003f61c>] (warn_slowpath_common) from [<c003f65c>] (warn_slowpath_null+0x1c/0x24)
[<c003f65c>] (warn_slowpath_null) from [<c02f7e10>] (gpiod_set_raw_value+0x40/0x4c)
[<c02f7e10>] (gpiod_set_raw_value) from [<c0308fbc>] (gpio_backlight_update_status+0x4c/0x74)
[<c0308fbc>] (gpio_backlight_update_status) from [<c030914c>] (gpio_backlight_probe+0x168/0x254)
[<c030914c>] (gpio_backlight_probe) from [<c0378fa8>] (platform_drv_probe+0x18/0x48)
[<c0378fa8>] (platform_drv_probe) from [<c0377c40>] (driver_probe_device+0x10c/0x238)
[<c0377c40>] (driver_probe_device) from [<c0376330>] (bus_for_each_drv+0x44/0x8c)
[<c0376330>] (bus_for_each_drv) from [<c0377afc>] (device_attach+0x74/0x8c)
[<c0377afc>] (device_attach) from [<c03771c4>] (bus_probe_device+0x88/0xb0)
[<c03771c4>] (bus_probe_device) from [<c03775c8>] (deferred_probe_work_func+0x64/0x94)
[<c03775c8>] (deferred_probe_work_func) from [<c00572e8>] (process_one_work+0x1b4/0x4bc)
[<c00572e8>] (process_one_work) from [<c00579d0>] (worker_thread+0x11c/0x398)
[<c00579d0>] (worker_thread) from [<c005dfd8>] (kthread+0xc8/0xe4)
[<c005dfd8>] (kthread) from [<c000e768>] (ret_from_fork+0x14/0x2c)
Fix this by using gpio_set_value_cansleep() as suggested in
drivers/gpio/gpiolib.c:2364. This is what the other backlight drivers
are also doing.
Signed-off-by: Tony Lindgren <tony@atomide.com>
--- a/drivers/video/backlight/gpio_backlight.c
+++ b/drivers/video/backlight/gpio_backlight.c
@@ -38,7 +38,8 @@ static int gpio_backlight_update_status(struct backlight_device *bl)
bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
brightness = 0;
- gpio_set_value(gbl->gpio, brightness ? gbl->active : !gbl->active);
+ gpio_set_value_cansleep(gbl->gpio,
+ brightness ? gbl->active : !gbl->active);
return 0;
}
next reply other threads:[~2014-05-09 1:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-09 1:24 Tony Lindgren [this message]
2014-05-09 2:25 ` [PATCH] backlight: gpio-backlight: Fix warning when the GPIO is on a I2C chip Jingoo Han
2014-05-09 3:09 ` Tony Lindgren
2014-05-09 3:42 ` Jingoo Han
2014-05-09 9:06 ` Linus Walleij
2014-05-13 1:36 ` Jingoo Han
2014-05-19 13:50 ` Lee Jones
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=20140509012454.GL2198@atomide.com \
--to=tony@atomide.com \
--cc=cooloney@gmail.com \
--cc=jg1.han@samsung.com \
--cc=lee.jones@linaro.org \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=plagnioj@jcrosoft.com \
--cc=tomi.valkeinen@ti.com \
/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).