ata mode at startup

[Søren Schmidt]

On 23May, 2008, at 16:43 , Julian Stacey wrote:

> phoemix at harmless.hu wrote:
>> Hello,
>> As known, FreeBSD sets the highest supported ATA mode, but  
>> sometimes it's
>> inproper, since the disk fails to work in this mode. This will be  
>> obsolate =
>> by
>> recent SATA drives, but PATA is still in use :)
>> I've though of the possibility of adding an "atamodetab" rc script,  
>> with wh=
>> ich
>> the administrator could specify the disk modes to set on startup.
> ......^^^^^^^^^^^^^ ....
>
> No good waiting for an admin to manually edit a table:
> An admin cant edit till FreeBSD boots.
> FreeBSD fails to boot on some older laptops eg
> 	http://www.berklix.com/~jhs/hardware/digital/
> 	http://www.berklix.com/~jhs/hardware/laptops/ 
> dell_latitude_xpi_p133st/
> unless one pre-knows FreeBSD magic like 	
> 	loader.conf hw.ata.ata_dma=0
> 	http://www.berklix.com/~jhs/hardware/laptops/#loader.conf
>
> A table in src/ that would automatically recognise flakey ATA hardware
> & reduce ambitious FreeBSD so it could boot, would be nice.

It would also be impossible to maintain, thats why the current knobs  
are there, if DMA fails you boot in "safe" mode ie PIO and then you  
can experiment to your hearts content what your flakey HW can take.

-Søren