Date

Okay, I admit. I skim the lkml from time to time.  And here's a gem from HPA about how the reality of life is:

``` {style="padding-left: 30px;"} First, you are assuming all devices are "sane". This is obviously wrong -- you're poking in hyperspace, and you don't know if you're going to hit someone's ancient controller card that perhaps drives a medical accelerator for all you know.

Second, you are assuming that devices you call "sane" don't have I/O ports with read side effects. Many, if not most, devices have some I/O ports with read side effects, especially read-clear semantics and/or queue drain operations.

Third, in the real world hardware is buggy. Not just a little, but severely so. Accessing a part of a device which is uninitialized, powered down or plain broken can wedge the device or the whole system.

In short, poking at I/O ports which you don't know what they are at best takes us bad to the bad old days of ISA probing (without the protection of customary address assignments); I think it has to be an absolutely last resort and would be reflective of utterly incompetent design. It is significantly worse than stealing random opcodes, Virtual PC-style, and that is also unacceptable. ```