On Thu, Jun 17, 2021 at 05:46:33PM +0300, Dmitry Osipenko wrote: > 17.06.2021 17:13, Guenter Roeck пишет: > ... > >> This is a device-tree based system, in particular it's NVIDIA Tegra30 > >> Nexus 7. The interrupt support was originally added to the lm90 driver > >> by Wei Ni who works at NVIDIA and did it for the Tegra boards. The Tegra > >> device-trees are specifying the trigger mask and apparently they all are > >> cargo-culted and wrong because they use IRQ_TYPE_LEVEL_HIGH, while it > > > > Be fair, no one is perfect. > > This is a very minor problem, so no wonder that nobody noticed or > bothered to fix it yet. I'm just clarifying the status here. > > >> should be IRQ_TYPE_EDGE_FALLING. > > > > It should probably be both IRQ_TYPE_EDGE_FALLING and IRQ_TYPE_EDGE_RISING, > > For now I see that the rising edge isn't needed, the TEMP_ALERT goes > HIGH by itself when temperature backs to normal. But I will try to > double check. > The point is that a sysfs event should be sent to userspace on both edges, not only when an alarm is raised. But, you are correct, IRQ_TYPE_EDGE_RISING is currently not needed since sysfs events are not generated. > > and the interrupt handler should call hwmon_notify_event() instead of > > clogging the kernel log, but that should be done in a separate patch. > > Thank you for suggestion, I will take a look. > > > Anyway, the tegra30 dts files in the upstream kernel either use > > IRQ_TYPE_LEVEL_LOW or no interrupts for nct1008. The Nexus 7 dts file > > in the upstream kernel has no interrupt configured (and coincidentally > > it was you who added that entry). Where do you see IRQ_TYPE_LEVEL_HIGH ? > > I have a patch that will add the interrupt property, it's stashed > locally for the next kernel release. > > IIUC, it's not only the Tegra30 dts, but all the TegraXXX boards that > use IRQ_TYPE_LEVEL_LOW are in the same position. I still don't see a IRQ_TYPE_LEVEL_HIGH, though. Thanks, Guenter > > >> The IRQF flag in devm_request_threaded_irq() overrides the trigger mask > >> specified in a device-tree. IIUC, the interrupt is used only by OF-based > >> devices, hence I think we could simply remove the IRQF flag from the > >> code and fix the device-trees. Does it sound good to you? > > > > Yes, that is a better approach. > > Thank you for reviewing this patch. I'll prepare v2.
