Messages in this thread | | | From | Jingoo Han <> | Subject | Re: [PATCH v3] backlight: corgi_lcd: Use gpio_set_value_cansleep() to avoid WARN_ON | Date | Wed, 05 Dec 2012 10:17:58 +0900 |
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On Wednesday, December 05, 2012 7:58 AM, Andrew Morton wrote > On Tue, 04 Dec 2012 14:28:15 +0900 > Jingoo Han <jg1.han@samsung.com> wrote: > > > From: Marko Katic <dromede@gmail.com> > > > > Changing backlight intensity on an Akita (Sharp Zaurus C-1000) > > triggers WARN_ON message: > > Well, I queued it up. > > > ... > > > > --- a/drivers/video/backlight/corgi_lcd.c > > +++ b/drivers/video/backlight/corgi_lcd.c > > @@ -408,11 +408,20 @@ static int corgi_bl_set_intensity(struct corgi_lcd *lcd, int intensity) > > /* Bit 5 via GPIO_BACKLIGHT_CONT */ > > cont = !!(intensity & 0x20) ^ lcd->gpio_backlight_cont_inverted; > > > > - if (gpio_is_valid(lcd->gpio_backlight_cont)) > > - gpio_set_value(lcd->gpio_backlight_cont, cont); > > + if (gpio_is_valid(lcd->gpio_backlight_cont)) { > > + if (gpio_cansleep(lcd->gpio_backlight_cont)) > > + gpio_set_value_cansleep(lcd->gpio_backlight_cont, cont); > > + else > > + gpio_set_value(lcd->gpio_backlight_cont, cont); > > + } > > But this looks utterly daft. Grant, these two things are the same - do > we need both of them?
Hi Andrew,
There is another difference, except for warning message. There is might_sleep_if(extra_checks) in gpio_set_value_cansleep().
Also, I saw the Documentation/gpio.txt as below:
172 /* GPIO OUTPUT */ 173 void gpio_set_value(unsigned gpio, int value); ... 213 /* GPIO OUTPUT, might sleep */ 214 void gpio_set_value_cansleep(unsigned gpio, int value);
Best regards, Jingoo Han
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