Hi Jon, On 19/04/16 15:14, Jon Hunter wrote: > > On 09/04/16 12:03, Marc Zyngier wrote: >> On Thu, 17 Mar 2016 14:19:09 +0000 >> Jon Hunter <jonathanh@xxxxxxxxxx> wrote: >> >>> The firmware parameter that contains the IRQ sense bits may also contain >>> other data. When return the IRQ type, bits outside of these sense bits >>> should be masked. If these bits are not masked and >>> irq_create_fwspec_mapping() is called to map an IRQ, then the comparison >>> of the type returned from irq_domain_translate() will never match >>> that returned by irq_get_trigger_type() (because this function masks the >>> none sense bits) and so we will always call irq_set_irq_type() to program >>> the type even if it was not really necessary. >>> >>> Currently, the downside to this is unnecessarily re-programmming the type >>> but nevertheless this should be avoided. >>> >>> The Tegra LIC, TI Crossbar and GIC-V3 irqchips all have client instances >>> (from reviewing the device-tree sources) where bits outside the IRQ sense >>> bits are set, but do not mask these bits. Therefore, ensure these bits >>> are masked for these irqchips. >> >> For GICv3, this shouldn't be the case. The DT clearly says that the 3rd >> field should only contain the trigger description. It looks like people >> have been copying their GICv2 DT and simply slapped the v3 description >> in the middle, without changing their interrupt specifiers. Duh. > > Hmmm ... I was just double checking on this for the gic-v3 by wading > through the DTS files, and may be there is no issue here. However, > looking at the current code it is a bit inconsistent between firmware > types ... > > static int gic_irq_domain_translate(struct irq_domain *d, > struct irq_fwspec *fwspec, > unsigned long *hwirq, > unsigned int *type) > { > if (is_of_node(fwspec->fwnode)) { > if (fwspec->param_count < 3) > return -EINVAL; > > switch (fwspec->param[0]) { > case 0: /* SPI */ > *hwirq = fwspec->param[1] + 32; > break; > case 1: /* PPI */ > *hwirq = fwspec->param[1] + 16; > break; > case GIC_IRQ_TYPE_LPI: /* LPI */ > *hwirq = fwspec->param[1]; > break; > default: > return -EINVAL; > } > > *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK; > return 0; > } > > if (is_fwnode_irqchip(fwspec->fwnode)) { > if(fwspec->param_count != 2) > return -EINVAL; > > *hwirq = fwspec->param[0]; > *type = fwspec->param[1]; That's because param[1] doesn't really come from the firmware. It is actually provided directly by acpi_dev_get_irq_type, so more or less guaranteed to be a valid value. Thanks, M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html