Messages in this thread | | | Subject | Re: [PATCH RESEND v2 3/5] extcon: extcon-max77693.c: Fix potential work-queue cancellation race | From | Chanwoo Choi <> | Date | Thu, 10 Jun 2021 18:43:28 +0900 |
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On 6/8/21 7:10 PM, Matti Vaittinen wrote: > The extcon IRQ schedules a work item. IRQ is requested using devm while > WQ is cancelld at remove(). This mixing of devm and manual unwinding has > potential case where the WQ has been emptied (.remove() was ran) but > devm unwinding of IRQ was not yet done. It may be possible the IRQ is > triggered at this point scheduling new work item to the already flushed > queue. > > According to the input documentation the input device allocated by > devm_input_allocate_device() does not need to be explicitly unregistered. > Use the new devm_work_autocancel() and remove the remove() to simplify the > code. > > Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> > Reviewed-by: Hans de Goede <hdegoede@redhat.com> > --- > > Please note that the change is compile-tested only. All proper testing is > highly appreciated. > --- > drivers/extcon/extcon-max77693.c | 17 +++++------------ > 1 file changed, 5 insertions(+), 12 deletions(-) > > diff --git a/drivers/extcon/extcon-max77693.c b/drivers/extcon/extcon-max77693.c > index 92af97e00828..1f1d9ab0c5c7 100644 > --- a/drivers/extcon/extcon-max77693.c > +++ b/drivers/extcon/extcon-max77693.c > @@ -5,6 +5,7 @@ > // Copyright (C) 2012 Samsung Electrnoics > // Chanwoo Choi <cw00.choi@samsung.com> > > +#include <linux/devm-helpers.h> > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/i2c.h> > @@ -1127,7 +1128,10 @@ static int max77693_muic_probe(struct platform_device *pdev) > platform_set_drvdata(pdev, info); > mutex_init(&info->mutex); > > - INIT_WORK(&info->irq_work, max77693_muic_irq_work); > + ret = devm_work_autocancel(&pdev->dev, &info->irq_work, > + max77693_muic_irq_work); > + if (ret) > + return ret; > > /* Support irq domain for MAX77693 MUIC device */ > for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) { > @@ -1254,22 +1258,11 @@ static int max77693_muic_probe(struct platform_device *pdev) > return ret; > } > > -static int max77693_muic_remove(struct platform_device *pdev) > -{ > - struct max77693_muic_info *info = platform_get_drvdata(pdev); > - > - cancel_work_sync(&info->irq_work); > - input_unregister_device(info->dock);
I think that you have to keep the input_unregister_device().
> - > - return 0; > -} > - > static struct platform_driver max77693_muic_driver = { > .driver = { > .name = DEV_NAME, > }, > .probe = max77693_muic_probe, > - .remove = max77693_muic_remove, > }; > > module_platform_driver(max77693_muic_driver); >
-- Best Regards, Chanwoo Choi Samsung Electronics
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