On Tue, Sep 9, 2014 at 12:40 AM, Lothar Waßmann <LW@xxxxxxxxxxxxxxxxxxx> wrote: > When using a GPIO driver whose accessor functions may sleep (e.g. an > I2C GPIO extender like PCA9554) the following warning is issued: > WARNING: CPU: 0 PID: 665 at drivers/gpio/gpiolib.c:2274 gpiod_get_raw_value+0x3c/0x48() > Modules linked in: > CPU: 0 PID: 665 Comm: kworker/0:2 Not tainted 3.16.0-karo+ #115 > Workqueue: events gpio_trig_work > [<c00142cc>] (unwind_backtrace) from [<c00118f8>] (show_stack+0x10/0x14) > [<c00118f8>] (show_stack) from [<c001bf10>] (warn_slowpath_common+0x64/0x84) > [<c001bf10>] (warn_slowpath_common) from [<c001bf4c>] (warn_slowpath_null+0x1c/0x24) > [<c001bf4c>] (warn_slowpath_null) from [<c020a1b8>] (gpiod_get_raw_value+0x3c/0x48) > [<c020a1b8>] (gpiod_get_raw_value) from [<c02f68a0>] (gpio_trig_work+0x1c/0xb0) > [<c02f68a0>] (gpio_trig_work) from [<c0030c1c>] (process_one_work+0x144/0x38c) > [<c0030c1c>] (process_one_work) from [<c0030ef8>] (worker_thread+0x60/0x5cc) > [<c0030ef8>] (worker_thread) from [<c0036dd4>] (kthread+0xb4/0xd0) > [<c0036dd4>] (kthread) from [<c000f0f0>] (ret_from_fork+0x14/0x24) > ---[ end trace cd51a1dad8b86c9c ]--- > > Fix this by using the _cansleep() variant of gpio_get_value(). > Good catch, I will merge this. Thanks, -Bryan > Signed-off-by: Lothar Waßmann <LW@xxxxxxxxxxxxxxxxxxx> > --- > drivers/leds/trigger/ledtrig-gpio.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c > index 35812e3..c86c418 100644 > --- a/drivers/leds/trigger/ledtrig-gpio.c > +++ b/drivers/leds/trigger/ledtrig-gpio.c > @@ -48,7 +48,7 @@ static void gpio_trig_work(struct work_struct *work) > if (!gpio_data->gpio) > return; > > - tmp = gpio_get_value(gpio_data->gpio); > + tmp = gpio_get_value_cansleep(gpio_data->gpio); > if (gpio_data->inverted) > tmp = !tmp; > > -- > 1.7.10.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
