Maybe I need to answer part of my question and ask another. I can see, by putting a printk into ../kernel/irq/handle.c:__do_IRQ that I normally get 3 interrupts with this 8541 board based on a linux-2.6.17.11 kernel. A cat /proc/interrupts shows enet_rx on interrupt 93, enet_tx on interrupt 94 and the serial port in interrupt 106.
I have a peripheral that sets irq to 16 and does a request_irq and this works in the 8541 board. But on the 8541 board, the printk from inside __do_IRQ shows the irq variable is zero, not 16. Can someone please help me understand the care and feeding of external interrupts in the 8541 a bit more completely? Charles -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Charles Krinke Sent: Thursday, April 26, 2007 11:36 AM To: [email protected] Cc: Randy Brown; Chris Carlson; Kevin Smith Subject: IRQ questions & puzzles I have a linux-2.6.17.11 source tree that has configs for two boards. One has an 8241 and the other has an 8541. The kernel code works fine on the 8241, but appears to lock up in my custom driver in the 8541 when interrupts are enabled. What I see happening, based on using a BDI to go/halt after the apparent lockup is that the kernel is spinning around in routines like kernel/irq/handle.c:__do_IRQ and an associated arch/powerpc/kernel/irq.c. It looks like the interrupt, which should be level triggered and at this point, is probably continuously asserted is causing the kernel to spin in a tight loop and be incapable of doing printk's out the serial port at 115200. This leads to a few questions: 1. I can see most everything comes from arch/ppc, but do_IRQ comes from arch/powerpc. Is that OK? 2. What is the most straightforward way to slow down a tight loop like this slow enough so I can printk what is happening. 3. What might be the likely scenarios leading to such a despicable state. Charles Krinke _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
