Stephen Warren wrote at Friday, September 02, 2011 1:28 PM: > Russell, Colin, > > The Tegra Harmony board contains a TPS6586x chip, which has an active-low > interrupt output. This is then fed to Tegra's PMC's PWR_INT pin, which can > be programmed to accept active-low or active-high interrupt signals. This > then feeds into a GIC interrupt. > > The problem is that the PMC appears to default to expecting the attached > signal to be active-high not active-low. > > At a driver level, it seems that IRQF_TRIGGER_LEVEL_LOW should be passed > to request_threaded_irq() to solve this. However, gic.c:gic_set_type() > prohibits IRQ_TYPE_* except LEVEL_HIGH and EDGE_RISING. > > I'm not quite sure how to solve this; should gic_set_type() be modified > to remove the restriction if gic_arch_extn.irq_set_type is present, and > assume that gic_arch_extn.irq_set_type will handle converting the input > signal from LEVEL_LOW to LEVEL_HIGH or EDGE_FALLING to EDGE_RISING? > > In at least some non-mainline kernels, this has been solved by having > individual board files poke PMC registers to invert the signal to the > gic's expected LEVEL_HIGH. However, I assume that's not a good solution > for mainline. > > Thanks. Russell, Colin, and thoughts on this? Should I simply modify gic_set_type() to allow LEVEL_LOW/EDGE_FALLING too? Thanks. -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
