Hi Thomas, Thanks a lot for your help!
But I still have some confusion. Could you please help to give some suggestions to me? 1) This device is a ACPI device, the hardware engineer designed it as falling edge interrupt trigger mode, does it need to re-work the hardware and modify it as rising edge trigger mode to suit the Linux APIC driver architecture? 2) Why does APIC driver not implement the irq_set_type method? if implement it, will supply more free space for the device driver developer(they can set the interrupt trigger mode by calling request_irq). Thank you! Carl On Wed, Feb 19, 2014 at 4:13 AM, Thomas Gleixner <[email protected]> wrote: > On Tue, 18 Feb 2014, carl peng wrote: > > Carl, sending the same mail twice within an hour does not speed up > things. It's quite likely that it gets ignored. > >> 1. Does it need to implement irq_set_type method in the ioapic_chip >> structure? > > No. The irq type is configured by the type of the interrupt or the > BIOS. > > ISA interrupts are always polarity zero edge triggered (historic) > > PCI interrupts are always polarity one level triggered > > PCIE interrupts are either legacy PCI or with MSI[X] always edge > triggered > >> 2. if no need to implement it, how can device driver set the trigger mode >> of APIC interrupt controller pin? > > Not at all. > > The device which is connected to one of the busses must follow the > specification of the bus. There is no choice. Any additional > requirements of the device to deal with external signals must be > handled by the device itself and converted to the appropriate bus > requirement. > > This all is configured by the kernel automatically through bus > detection and BIOS tables. > > Thanks, > > tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
