I'm running RTLinux 3.1/2.4.18 and am having a system configuration problem with my target hardware. It is a PC based system with a Celeron processor, an AGP video card and several PCI devices. These PCI devices include a Realtek 8139 Ethernet card, a multi-port serial card and a digital I/O card.
My software consists of a RT module which services the interrupt on the digital I/O card (and also does some polled I/O), and interfaces to a userspace application via FIFOs. My realtime module uses pci_find_subsys() to find the details of my I/O card, and then I use rtl_request_irq() to install my interrupt service routine. The problem that I am experiencing, is that the motherboard's BIOS is assigning the same IRQ to the digital I/O board and other devices (namely the ethernet board). I wrote my ISR to verify that my board generated the interrupt, but apparently RTLinux does not permit sharing of IRQs with non-RT tasks (ala SA_INTERRUPT style), and my other devices sharing that IRQ aren't working. I've attempted to change the IRQ via setpci calls, but from what I read this only changes the scratch area that the BIOS stuffs the data to, not the actual settings. My experience agrees with this, since although I change the IRQ via setpci, lspci still shows it at the old IRQ. My BIOS has no settings to let me reserve resources for a specific slot, and I can't seem to find a way to make this work. I realize that sharing a RT interrupt with a non-RT task would hurt latencies, but if I could get it to work, I'd be happy. I've fooled with Pnp/non-PnP settings, but there doesn't seem to be anything that I can do to guarantee a specific interrupt for my digital I/O card. I'd be even happier if somebody could tell me how to really change the digital I/O board's IRQ via software, if it's even possible. It's a custom board which uses a PLX Technology, Inc. PCI <-> IOBus Bridge (rev 01) chip. Any ideas? Regards, Jim Evans R&D Software Engineer [EMAIL PROTECTED] _______________________________________________ Rtl mailing list [EMAIL PROTECTED] http://www2.fsmlabs.com/mailman/listinfo.cgi/rtl
