Re: [PATCH v3 3/8] extconn: Clean-up few drivers by using managed work init
From: Hans de Goede
Date: Tue Mar 23 2021 - 10:00:58 EST
Hi,
On 3/23/21 2:57 PM, Matti Vaittinen wrote:
> Few drivers implement remove call-back only for ensuring a delayed
> work gets cancelled prior driver removal. Clean-up these by switching
> to use devm_delayed_work_autocancel() instead.
>
> Additionally, this helps avoiding mixing devm and manual resource
> management and cleans up a (theoretical?) bug from extconn-palmas.c
> and extcon-qcom-spmi-misc.c where (devm managed)IRQ might schedule
> new work item after wq was cleaned at remove().
>
> This change is compile-tested only. All testing is appreciated.
>
> Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
Thanks, patch looks good to me:
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Note that this is not just a cleanup, it also actually fixes a
couple of driver-unbind races where the work was stopped before
the IRQ is free-ed, so there is a race where the work can be
restarted.
Regards,
Hans
> ---
> Changelog from RFCv2:
> - RFC dropped. No functional changes.
>
> drivers/extcon/extcon-gpio.c | 15 ++++-----------
> drivers/extcon/extcon-intel-int3496.c | 16 ++++------------
> drivers/extcon/extcon-palmas.c | 17 ++++++-----------
> drivers/extcon/extcon-qcom-spmi-misc.c | 17 ++++++-----------
> 4 files changed, 20 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
> index c211222f5d0c..4105df74f2b0 100644
> --- a/drivers/extcon/extcon-gpio.c
> +++ b/drivers/extcon/extcon-gpio.c
> @@ -9,6 +9,7 @@
> * (originally switch class is supported)
> */
>
> +#include <linux/devm-helpers.h>
> #include <linux/extcon-provider.h>
> #include <linux/gpio/consumer.h>
> #include <linux/init.h>
> @@ -112,7 +113,9 @@ static int gpio_extcon_probe(struct platform_device *pdev)
> if (ret < 0)
> return ret;
>
> - INIT_DELAYED_WORK(&data->work, gpio_extcon_work);
> + ret = devm_delayed_work_autocancel(dev, &data->work, gpio_extcon_work);
> + if (ret)
> + return ret;
>
> /*
> * Request the interrupt of gpio to detect whether external connector
> @@ -131,15 +134,6 @@ static int gpio_extcon_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int gpio_extcon_remove(struct platform_device *pdev)
> -{
> - struct gpio_extcon_data *data = platform_get_drvdata(pdev);
> -
> - cancel_delayed_work_sync(&data->work);
> -
> - return 0;
> -}
> -
> #ifdef CONFIG_PM_SLEEP
> static int gpio_extcon_resume(struct device *dev)
> {
> @@ -158,7 +152,6 @@ static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
>
> static struct platform_driver gpio_extcon_driver = {
> .probe = gpio_extcon_probe,
> - .remove = gpio_extcon_remove,
> .driver = {
> .name = "extcon-gpio",
> .pm = &gpio_extcon_pm_ops,
> diff --git a/drivers/extcon/extcon-intel-int3496.c b/drivers/extcon/extcon-intel-int3496.c
> index 80c9abcc3f97..fb527c23639e 100644
> --- a/drivers/extcon/extcon-intel-int3496.c
> +++ b/drivers/extcon/extcon-intel-int3496.c
> @@ -11,6 +11,7 @@
> */
>
> #include <linux/acpi.h>
> +#include <linux/devm-helpers.h>
> #include <linux/extcon-provider.h>
> #include <linux/gpio/consumer.h>
> #include <linux/interrupt.h>
> @@ -101,7 +102,9 @@ static int int3496_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> data->dev = dev;
> - INIT_DELAYED_WORK(&data->work, int3496_do_usb_id);
> + ret = devm_delayed_work_autocancel(dev, &data->work, int3496_do_usb_id);
> + if (ret)
> + return ret;
>
> data->gpio_usb_id = devm_gpiod_get(dev, "id", GPIOD_IN);
> if (IS_ERR(data->gpio_usb_id)) {
> @@ -155,16 +158,6 @@ static int int3496_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int int3496_remove(struct platform_device *pdev)
> -{
> - struct int3496_data *data = platform_get_drvdata(pdev);
> -
> - devm_free_irq(&pdev->dev, data->usb_id_irq, data);
> - cancel_delayed_work_sync(&data->work);
> -
> - return 0;
> -}
> -
> static const struct acpi_device_id int3496_acpi_match[] = {
> { "INT3496" },
> { }
> @@ -177,7 +170,6 @@ static struct platform_driver int3496_driver = {
> .acpi_match_table = int3496_acpi_match,
> },
> .probe = int3496_probe,
> - .remove = int3496_remove,
> };
>
> module_platform_driver(int3496_driver);
> diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
> index a2852bcc5f0d..d2c1a8b89c08 100644
> --- a/drivers/extcon/extcon-palmas.c
> +++ b/drivers/extcon/extcon-palmas.c
> @@ -9,6 +9,7 @@
> * Author: Hema HK <hemahk@xxxxxx>
> */
>
> +#include <linux/devm-helpers.h>
> #include <linux/module.h>
> #include <linux/interrupt.h>
> #include <linux/platform_device.h>
> @@ -237,7 +238,11 @@ static int palmas_usb_probe(struct platform_device *pdev)
> palmas_usb->sw_debounce_jiffies = msecs_to_jiffies(debounce);
> }
>
> - INIT_DELAYED_WORK(&palmas_usb->wq_detectid, palmas_gpio_id_detect);
> + status = devm_delayed_work_autocancel(&pdev->dev,
> + &palmas_usb->wq_detectid,
> + palmas_gpio_id_detect);
> + if (status)
> + return status;
>
> palmas->usb = palmas_usb;
> palmas_usb->palmas = palmas;
> @@ -359,15 +364,6 @@ static int palmas_usb_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int palmas_usb_remove(struct platform_device *pdev)
> -{
> - struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
> -
> - cancel_delayed_work_sync(&palmas_usb->wq_detectid);
> -
> - return 0;
> -}
> -
> #ifdef CONFIG_PM_SLEEP
> static int palmas_usb_suspend(struct device *dev)
> {
> @@ -422,7 +418,6 @@ static const struct of_device_id of_palmas_match_tbl[] = {
>
> static struct platform_driver palmas_usb_driver = {
> .probe = palmas_usb_probe,
> - .remove = palmas_usb_remove,
> .driver = {
> .name = "palmas-usb",
> .of_match_table = of_palmas_match_tbl,
> diff --git a/drivers/extcon/extcon-qcom-spmi-misc.c b/drivers/extcon/extcon-qcom-spmi-misc.c
> index 6b836ae62176..74d57d951b68 100644
> --- a/drivers/extcon/extcon-qcom-spmi-misc.c
> +++ b/drivers/extcon/extcon-qcom-spmi-misc.c
> @@ -7,6 +7,7 @@
> * Stephen Boyd <stephen.boyd@xxxxxxxxxx>
> */
>
> +#include <linux/devm-helpers.h>
> #include <linux/extcon-provider.h>
> #include <linux/init.h>
> #include <linux/interrupt.h>
> @@ -80,7 +81,11 @@ static int qcom_usb_extcon_probe(struct platform_device *pdev)
> }
>
> info->debounce_jiffies = msecs_to_jiffies(USB_ID_DEBOUNCE_MS);
> - INIT_DELAYED_WORK(&info->wq_detcable, qcom_usb_extcon_detect_cable);
> +
> + ret = devm_delayed_work_autocancel(dev, &info->wq_detcable,
> + qcom_usb_extcon_detect_cable);
> + if (ret)
> + return ret;
>
> info->irq = platform_get_irq_byname(pdev, "usb_id");
> if (info->irq < 0)
> @@ -105,15 +110,6 @@ static int qcom_usb_extcon_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int qcom_usb_extcon_remove(struct platform_device *pdev)
> -{
> - struct qcom_usb_extcon_info *info = platform_get_drvdata(pdev);
> -
> - cancel_delayed_work_sync(&info->wq_detcable);
> -
> - return 0;
> -}
> -
> #ifdef CONFIG_PM_SLEEP
> static int qcom_usb_extcon_suspend(struct device *dev)
> {
> @@ -149,7 +145,6 @@ MODULE_DEVICE_TABLE(of, qcom_usb_extcon_dt_match);
>
> static struct platform_driver qcom_usb_extcon_driver = {
> .probe = qcom_usb_extcon_probe,
> - .remove = qcom_usb_extcon_remove,
> .driver = {
> .name = "extcon-pm8941-misc",
> .pm = &qcom_usb_extcon_pm_ops,
>