Messages in this thread | | | Date | Fri, 21 May 2010 12:21:41 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] drivers/gpio/it8761e_gpio: check return value of gpiochip_remove() |
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On Wed, 19 May 2010 17:28:33 +0200 Daniel Mack <daniel@caiaq.de> wrote:
> This eliminates the following build warning: > > drivers/gpio/it8761e_gpio.c: In function ___it8761e_gpio_exit___: > drivers/gpio/it8761e_gpio.c:220: warning: ignoring return value of ___gpiochip_remove___, declared with attribute warn_unused_result > > Signed-off-by: Daniel Mack <daniel@caiaq.de> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Denis Turischev <denis@compulab.co.il> > --- > drivers/gpio/it8761e_gpio.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/gpio/it8761e_gpio.c b/drivers/gpio/it8761e_gpio.c > index 753219c..a524bd8 100644 > --- a/drivers/gpio/it8761e_gpio.c > +++ b/drivers/gpio/it8761e_gpio.c > @@ -217,7 +217,10 @@ gpiochip_add_err: > static void __exit it8761e_gpio_exit(void) > { > if (gpio_ba) { > - gpiochip_remove(&it8761e_gpio_chip); > + int ret = gpiochip_remove(&it8761e_gpio_chip); > + > + WARN(ret, "%s(): gpiochip_remove() failed, ret=%d\n", > + __func__, ret); > > release_region(gpio_ba, GPIO_IOSIZE); > gpio_ba = 0;
So I just looked through ten-odd gpio drivers to see how they handle gpiochip_remove() failures. Big mess.
All of them do some form of printk, with no consistency.
Some of them bale out on error, leaking resources. Others just proceed to release the possibly-in-use resources.
I'd suggest that gpiochip_remove() itself emit the warning, so we can remove zillions of inconsistent warnings from drivers.
I'd also suggest that someone get down and work out what a suitable recovery strategy is. Probably, just leaking the possibly-still-used resources is the safest approach. Once the strategy is decided, lots of drivers need work.
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