Subject: Interrupt Priorities on the footbridge...
To: None <port-arm32@netbsd.org>
From: Bruce Martin <brucem@cat.co.za>
List: port-arm32
Date: 05/10/2000 11:23:54
We are currently experiencing problems with two devices on our EBSA285-based
board, running NetBSD/arm32. One device (i2c controller) is running at
IPL_BIO, and another (Serial chip) is running at IPL_TTY. The serial chip
runs fine under normal conditions, but when we use the i2c controller a lot,
the Serial chip seems to battle to meet its interrupt timing requirements,
and hangs up.

In NetBSD's footbridge irq scheme, are there actually 8 different priority
levels, or are there actually less, with some IPL's actually sharing equal
priorities?

Will a higher IPL irq actually interrupt a lower IPL irq?

Thanks
 Bruce Martin