Re: [PATCH] ide write barrier support

[Jeff Garzik <jgarzik@pobox.com>]

Jens Axboe wrote:
> On Mon, Oct 13 2003, Jeff Garzik wrote:
> 
>>Matthias Andree wrote:
>>
>>>On Mon, 13 Oct 2003, Jens Axboe wrote:
>>>
>>>
>>>
>>>>Forward ported and tested today (with the dummy ext3 patch included),
>>>>works for me. Some todo's left, but I thought I'd send it out to gauge
>>>>interest. TODO:
>>>>
>>>>- Detect write cache setting and only issue SYNC_CACHE if write cache is
>>>>enabled (not a biggy, all drives ship with it enabled)
>>>
>>>
>>>Yup, and I disable it on all drives at boot time at the latest.
>>>
>>>Is there a status document that lists
>>>
>>>- what SCSI drivers support write barriers
>>> (I'm interested in sym53c8xx_2 if that matters)
>>>
>>>- what IDE drivers support write barriers
>>> (VIA for AMD and Intel for PII/PIII/P4 chip sets here)
>>
>>The device is the entity that does, or does not, support flush-cache... 
>> All IDE chipsets support flush-cache... it's just another IDE command.
> 
> 
> Well drivers need to support it, too. IDE is supported, and that covers
> all devices that support it. It's not implemented on SCSI at all right
> now, that's coming up.

I do not see the need for write barrier support in 
drivers/ide/pci/{via82cxxx,piix,}.c, which is the question the original 
poster was asking.

Low-level chipset drivers should _not_ need to support it, the subsystem 
can do that.

	Jeff