Re: libata FUA revisited

Jeff Garzik
2007-02-16T18:15:01Z

Tejun Heo wrote:
> Hello,
>
> Robert Hancock wrote:
> [--correct summary snipped--]
>> Given the above, what I'm proposing to do is:
>>
>> -Remove the blacklisting of Maxtor BANC1G10 firmware for FUA. If we
>> need to FUA-blacklist any drives this should likely be added to the
>> existing "horkage" mechanism we now have. However, at this point I
>> don't think that's needed, considering that I've seen no conclusive
>> evidence that any drive has ever been established to have broken FUA.
>
> Agreed.
>
>> -Add a new port flag ATA_FLAG_NO_FUA to indicate that a controller
>> can't handle FUA commands, and add that flag to sata_sil. Force FUA
>> off on any drive connected to a controller with this bit set.
>>
>> There was some talk that sata_mv might have this problem, but I
>> believe the conclusion was that it didn't. The only controllers that
>> would are ones that actually try to interpret the ATA command codes
>> and don't know about WRITE DMA FUA.
>
> I think it would be better to add ATA_FLAG_FUA instead of ATA_FLAG_NO_FUA.

This is an interesting (if small) problem. I would propose a third
option: add ATA_FLAG_NO_FUA to applicable /SATA/ drivers, but leave
those without ATA_FLAG_SATA alone.

Jeff