Re: [PATCH 9/11] Panic delay fix

From: Dmitry Torokhov
Date: Thu Feb 08 2007 - 16:37:57 EST


On 2/8/07, Zachary Amsden <zach@xxxxxxxxxx> wrote:
Dmitry Torokhov wrote:
>
> However I am not really fond of idea of adding constructs like this
> all over the code:
>
> #define USE_REAL_TIME_DELAY_I_REALLY_MEAN_IT_THIS_TIME_I_SWEAR
>
> as the time passes... Drivers should be blissfully ignorant of being
> run on virtual hardware.

I agree in general, but there are two uses for this ugly construct. One
is for drivers and isolated sections of code which actually interact
with the real world. They need real time delays. The only two examples
so far are SMP coprocessor bootstrapping and blinking LEDs with a
recognizable frequency. I don't expect many more to show up.


I am pretty sure that using that construct inside of i8042 is wrong -
the host OS should handle hardware access/delay issues. Have you
verified that fixing kerne/panic.c to call i8042_panic_blink once per
1 ms (as it happens on native running kernel) does not produce the
desired blinking?

--
Dmitry
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