> Dear Friends, > I am sending a mail after a long time. I am facing a problem now. Please > help me to come out of this. > > Environment: > ~~~~~~~~~~~~ > RT-Linux - Version 3.1 > Linux - 2.4.16 with RT patch from contribution > > Hardware > ~~~~~~~~ > Pentium III - 700 MHz > 128 MB SDRAM > 40GB HAR DISK > > ADD-ON Module > ~~~~~~~~~~~~~~ > Supports PCI Ver 2.1 > Memory Requirement - 1 MB PCI > IO Requirement - 256 bytes I/O > IRQ - 1 Line INT A > > > We are developing a driver for a PCI add-on module which is actually a > communication add-on like RS-422 and 1553B. The problem here is if I put > more than one PCI add-on (same module) in the same PC, I am not able to > service interrupts properly. > Because, both are sharing the same interrupt the line. When I program the > BIOS to allocate different IRQs there is no problem. > > Please tell me wheather RT-Linux supports IRQ sharing, if so how to > implement that.
IRQ sharing as in Linux by setting the SA_SHIRQ flag is not supported in RTLinux rtl_request_irq, if you want to share interrupts between multiple devices (which would increas latency substantially) you will have to implement it by probing all devices in your interrupt handler your selfe. There is no list of devices like in Linux that will be stepped through to check each of the IRQ-sharing devices but if there is a simple way of checking status of the devices (reading some register) it should not be hard to implement in the hardrealtime interrupt handler by simply letting it check all the relevant card-registers befor processing the interrupt handlers body. If you want to share interrupts between RT and non-RT that may be somewhat harder to do - the RT-handler would have to check all rt-devices and if non issued the interrupt pend the interrupt for linux to process. hofrat -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
