On Sun, Jul 30, 2023 at 10:30:56PM +0200, Krzysztof Kozlowski wrote: > On 29/07/2023 18:08, Svyatoslav Ryhel wrote: > > From: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> > > > > Implement driver for hot-plugged I2C busses, where some devices on > > a bus are hot-pluggable and their presence is indicated by GPIO line. [...] > > + priv->irq = platform_get_irq(pdev, 0); > > + if (priv->irq < 0) > > + return dev_err_probe(&pdev->dev, priv->irq, > > + "failed to get IRQ %d\n", priv->irq); > > + > > + ret = devm_request_threaded_irq(&pdev->dev, priv->irq, NULL, > > + i2c_hotplug_interrupt, > > + IRQF_ONESHOT | IRQF_SHARED, > > Shared IRQ with devm is a recipe for disaster. Are you sure this is a > shared one? You have a remove() function which also points that it is > not safe. You can: > 1. investigate to be sure it is 100% safe (please document why do you > think it is safe) Could you elaborate on what is unsafe in using devm with shared interrupts (as compared to non-shared or not devm-managed)? The remove function is indeed reversing the order of cleanup. The shutdown path can be fixed by removing `remove()` and adding `devm_add_action_or_reset(...deactivate)` before the IRQ is registered. Best Regards Michał Mirosław
