From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <38EA7BD9.C24774EB@embeddededge.com> Date: Tue, 04 Apr 2000 19:33:45 -0400 From: Dan Malek MIME-Version: 1.0 To: Marcus Sundberg CC: Ruedi Hofer , linuxppc-embedded@lists.linuxppc.org Subject: Re: PCMCIA support for 860 References: <38E9BA8F.913681C7@ascom.ch> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Marcus Sundberg wrote: > > Ruedi Hofer writes: > > Does someone have a clue on that? Is request_irq and request_8xxirq related?? Sort of. The MPC8xx has an internal interrupt controller. The Linux community seems to think the world is 8259s and PCI/ISA bus. Mapping request_irq into the 8xx interrupt controller was attempted, but didn't provide the proper results. The request_8xxirq function is used by all integrated device drivers (serial, Ethernet, TDM/audio, USB, SPI, I2C, PCMCIA, general purpose I/O pins, etc.), as they know they are using the internal interrupt controller. In the case of boards with PCI/ISA bridges, the request_irq is also enabled because there is a downstream 8259 controller. Not defining this when there is no 8259 causes drivers that would attempt to use this to fail. It is nice to know this at build time, rather than wondering why things are crashing or not working once the system is booted. This also presents a challenge for PCMCIA devices. All of these drivers (or supporting functions) want to install interrupt handlers using request_irq, which doesn't make sense on the 8xx. I have the ATA/IDE patch to install the interrupt handler, but other devices may also need interrupt handler patches. -- Dan ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/