Re: [RFC][PATCH] at91_ide driver

[Stanislaw Gruszka <stf_xl@wp.pl>]

Thursday 22 January 2009 10:44:10 Sergei Shtylyov napisał(a):
> Hello.
> 
> Stanislaw Gruszka wrote:
> 
> >>    Besides, we have ide_timing_compute() doing the same thing.
> >>     
> > I'm trying use it, but have too bigger results - 1 or 2 cycles is added.
> >   
> 
>    That's most probably because ide_timing_compute() assumes non-zero 
> minimum recovery time for PIO modes 0 to 2 (libata does the same) -- 
> that actually smells of over-caution. It then tries to stretch the 
> active time if the sum of active and recovery times is less than cycle 
> time (all quantized already).
Hmm, why active time is stretched. IMHO it is better to stretch inactive
time (t2i), such it can be divided into setup (t1) and recovery time (t9 with t6z).
Otherwise sum of t1 + t2 + max(t9, t2i -  t1)  will be longer than cycle time t0.

Stanislaw Gruszka