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[83.28.191.6]) by smtp.gmail.com with ESMTPSA id o5-v6sm591061ljh.75.2019.02.08.13.37.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 08 Feb 2019 13:37:02 -0800 (PST) Subject: Re: [PATCH v2] Input: cap11xx - switch to using set_brightness_blocking() To: Dmitry Torokhov , Sven Van Asbroeck Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190208075739.GA95091@dtor-ws> From: Jacek Anaszewski Message-ID: <1a610ebf-6fbd-2846-b57c-ef4e1f4e2dd5@gmail.com> Date: Fri, 8 Feb 2019 22:37:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190208075739.GA95091@dtor-ws> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dmitry, Thank you for the update. On 2/8/19 8:57 AM, Dmitry Torokhov wrote: > Updating LED state requires access to regmap and therefore we may sleep, > so we could not do that directly form set_brightness() method. > Historically we used private work to adjust the brightness, but with the > introduction of set_brightness_blocking() we no longer need it. > > As a bonus, not having our own work item means we do not have > use-after-free issue as we neglected to cancel outstanding work on > driver unbind. > > Reported-by: Sven Van Asbroeck > Reviewed-by: Sven Van Asbroeck > Signed-off-by: Dmitry Torokhov > --- > > v2: no longer checking current brightness before trying to update since > regmap should take care of caching and skipping updates when needed > (Jacek). > > drivers/input/keyboard/cap11xx.c | 35 ++++++++++---------------------- > 1 file changed, 11 insertions(+), 24 deletions(-) > > diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c > index 312916f99597..73686c2460ce 100644 > --- a/drivers/input/keyboard/cap11xx.c > +++ b/drivers/input/keyboard/cap11xx.c > @@ -75,9 +75,7 @@ > struct cap11xx_led { > struct cap11xx_priv *priv; > struct led_classdev cdev; > - struct work_struct work; > u32 reg; > - enum led_brightness new_brightness; > }; > #endif > > @@ -233,30 +231,21 @@ static void cap11xx_input_close(struct input_dev *idev) > } > > #ifdef CONFIG_LEDS_CLASS > -static void cap11xx_led_work(struct work_struct *work) > +static int cap11xx_led_set(struct led_classdev *cdev, > + enum led_brightness value) > { > - struct cap11xx_led *led = container_of(work, struct cap11xx_led, work); > + struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev); > struct cap11xx_priv *priv = led->priv; > - int value = led->new_brightness; > > /* > - * All LEDs share the same duty cycle as this is a HW limitation. > - * Brightness levels per LED are either 0 (OFF) and 1 (ON). > + * All LEDs share the same duty cycle as this is a HW > + * limitation. Brightness levels per LED are either > + * 0 (OFF) and 1 (ON). > */ > - regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL, > - BIT(led->reg), value ? BIT(led->reg) : 0); > -} > - > -static void cap11xx_led_set(struct led_classdev *cdev, > - enum led_brightness value) > -{ > - struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev); > - > - if (led->new_brightness == value) > - return; > - > - led->new_brightness = value; > - schedule_work(&led->work); > + return regmap_update_bits(priv->regmap, > + CAP11XX_REG_LED_OUTPUT_CONTROL, > + BIT(led->reg), > + value ? BIT(led->reg) : 0); > } > > static int cap11xx_init_leds(struct device *dev, > @@ -299,7 +288,7 @@ static int cap11xx_init_leds(struct device *dev, > led->cdev.default_trigger = > of_get_property(child, "linux,default-trigger", NULL); > led->cdev.flags = 0; > - led->cdev.brightness_set = cap11xx_led_set; > + led->cdev.brightness_set_blocking = cap11xx_led_set; > led->cdev.max_brightness = 1; > led->cdev.brightness = LED_OFF; > > @@ -312,8 +301,6 @@ static int cap11xx_init_leds(struct device *dev, > led->reg = reg; > led->priv = priv; > > - INIT_WORK(&led->work, cap11xx_led_work); > - > error = devm_led_classdev_register(dev, &led->cdev); > if (error) { > of_node_put(child); > Acked-by: Jacek Anaszewski -- Best regards, Jacek Anaszewski