Re: [PATCH] (2.6.20-rc7) cmd64x: fix PIO mode setup (take 2)

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello, I wrote:

>>> Index: linux-2.6/drivers/ide/pci/cmd64x.c
>>> ===================================================================
>>> --- linux-2.6.orig/drivers/ide/pci/cmd64x.c
>>> +++ linux-2.6/drivers/ide/pci/cmd64x.c

>> While this was always incorrectly setting PIO4, the PIO4 is "the 
>> usual" case
>> and for this driver we need to program PIO explicitly even when using 
>> DMA.

>    Hm, why it's *so* special, i.e. why almost all the other drivers can 
> get away without it (the majority seems to have autotune set *only* if 
> hwif->dma_base is seen as 0 in the init_hwif() method? :-/

>> The core code doesn't program PIO mode unless told to (->autotune flag 
>> == 1)
>> so after the above change PIO mode won't be programmed et all.

>> I think that we now need to set ->autotune unconditionally in 
>> init_hwif_cmd64x().

   Don't think we *need* to. Look at the code at the end of init_chipset() 
method.  Those values it writes to ARTTIM/DRWTIM registers already matches 
PIO4!  That's another question what this code is doing there, being both 
duplicate and misplaced. :-)

>    No problem.  This actually seems the right thing to do in all 
> drivers, just like the libata core does. :-)

MBR, Sergei