Re: [patch] scsi: fix crash in gdth_timeout()

[Linus Torvalds <torvalds@linux-foundation.org>]

On Mon, 15 Oct 2007, Alan Cox wrote:
> 
> For some things. I do it a bit because you can use it to fake
> failures that are tricky to do in the real world. It won't tell you the
> driver works but its suprisingly good for testing for races (forcing IRQ
> delivery at specific points), buggy hardware you don't posess, and things
> like media failures and timeouts your real hardware refuses to do.

Heh. I do agree that you likely find bugs, even if quite often it's 
exactly because the behaviour is something that will never happen on real 
hardware.

But failure testing is very useful - I forget who it was who debugged some 
driver by taking a CD and just scrathing it mercilessly to induce read 
errors ;)

Having a really *bad* HW emulator can certainly work that way too, even if 
it also would probably end up hitting just a few of the potential error 
paths..

			Linus