Mark M. Hoffman wrote: > * Philip Edelbrock <phil at edgedesign.us> [2003-07-29 09:50:45 -0700]: > >>Jean Delvare wrote: >>My idea of the ideal driver is that it is almost transparent to the >>hardware. The less caching, the better. > > Much as I try, I can't jump off the fence here. OOH, it seems wasteful to > keep re-reading what are almost certainly non-volatile h/w registers. OTOH, > what are we optimizing here? - a special purpose slow bus that has nothing > better to do (I2C); or an insignificant amount of ISA port IO. Don't under-estimate the delays associated with doing ISA port I/O. It can take *thousands* of clock cycles to perform just one port I/O instruction. The kernel even uses I/O to port 0x80 as a short timing delay. :v) -- Philip Pokorny, Director of Engineering Tel: 415-358-2635 Fax: 415-358-2646 Toll Free: 888-PENGUIN PENGUIN COMPUTING, INC. www.penguincomputing.com
