On Mon, 30 Sep 2024 17:36:20 +0100, Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx> wrote: > > Hi Marc, > > Thanks for your feedback. > > > From: Marc Zyngier <maz@xxxxxxxxxx> > > Sent: Monday, September 30, 2024 4:50 PM > > To: Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx> > > Subject: Re: [PATCH] irqchip/renesas-rzg2l: Fix missing put_device > > > > On Mon, 30 Sep 2024 15:55:39 +0100, > > Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx> wrote: > > > > > > rzg2l_irqc_common_init calls of_find_device_by_node, but the > > > corresponding put_device call is missing. > > > > > > Make sure we call put_device both when failing and when succeeding. > > > > What sort of lifetime are you trying to enforce? > > Function rzg2l_irqc_common_init uses pdev->dev until its very end. > My understanding is that we should decrement the reference counter > once we are fully done with it. Is my understanding correct? "done with it" is what scares me. Specially when I see code like this: rzg2l_irqc_data = devm_kzalloc(&pdev->dev, sizeof(*rzg2l_irqc_data), GFP_KERNEL); if (!rzg2l_irqc_data) return -ENOMEM; rzg2l_irqc_data->irqchip = irq_chip; rzg2l_irqc_data->base = devm_of_iomap(&pdev->dev, pdev->dev.of_node, 0, NULL); if (IS_ERR(rzg2l_irqc_data->base)) return PTR_ERR(rzg2l_irqc_data->base); If you drop the reference on the device, you are allowing it to be removed, and everything the driver cares about to disappear behind its back. I can't really see how this is safe, because in general, removing an interrupt controller driver from the system is a pretty bad idea, and I'm worried that's you are implicitly enabling. M. -- Without deviation from the norm, progress is not possible.
