On Tue, 31 Jul 2018, Thomas Gleixner wrote: > On Mon, 30 Jul 2018, Bjorn Helgaas wrote: > > > [+cc maintainers of possibly erroneous callers of request_threaded_irq()] > > > > On Mon, Jul 30, 2018 at 04:30:28PM -0500, Bjorn Helgaas wrote: > > > [+cc Thomas, Christoph, LKML] > > > > > > On Mon, Jul 30, 2018 at 12:03:42AM +0200, Heiner Kallweit wrote: > > > > If we have a threaded interrupt with the handler being NULL, then > > > > request_threaded_irq() -> __setup_irq() will complain and bail out > > > > if the IRQF_ONESHOT flag isn't set. Therefore check for the handler > > > > being NULL and set IRQF_ONESHOT in this case. > > > > > > > > This change is needed to migrate the mei_me driver to > > > > pci_alloc_irq_vectors() and pci_request_irq(). > > > > > > > > Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> > > > > > > I'd like an ack from Thomas because this requirement about IRQF_ONESHOT > > > usage isn't mentioned in the request_threaded_irq() function doc or > > > Documentation/ > > > > Possibly these other request_threaded_irq() callers are similarly > > broken? I can't tell for sure about tda998x_create(), but all the > > others certainly call request_threaded_irq() with "handler == NULL" > > and irqflags that do not contain IRQF_ONESHOT: > > > > max8997_muic_probe() > > request_threaded_irq(virq, NULL, ..., IRQF_NO_SUSPEND, ...) > > > > tda998x_create() > > request_threaded_irq(client->irq, NULL, ..., irqd_get_trigger_type(), ...) > > (I can't tell what irqd_get_trigger_type() does) > > It reads the trigger type back from the irq chip (level/edge/polarity) but > does not return with the ONESHOT bit set. > > > ab8500_btemp_probe() > > ab8500_charger_probe() > > request_threaded_irq(irq, NULL, ..., IRQF_SHARED | IRQF_NO_SUSPEND, ...) > > SHARED is interesting .... > > > lp8788_set_irqs() > > request_threaded_irq(virq, NULL, ..., 0, ...) > > > > max77686_rtc_probe() > > request_threaded_irq(info->virq, NULL, ..., 0, ...) > > > > wm8350_register_irq() > > request_threaded_irq(irq + wm8350->irq_base, NULL, ..., flags, ...) > > (I think all callers of wm8350_register_irq() supply 0 for "flags") > > Indeed. This all looks pretty much wrong. No idea why nobody ever noticed. I guess not many people (myself included) know the intricacies well enough to have noticed. This probably coupled with insufficient checking/warning about such practices in the IRQ subsystem. There are quite a few different devices here, so my assumption would be that interrupt handling still works in these cases. If we know certain configurations are incorrect or incompatible, might I suggest we add some form of alert to bring these to the attention of unknowing contributors? -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
