DragonFly BSD
DragonFly kernel List (threaded) for 2003-10
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Re: ataNG

From: Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>
Date: Sun, 26 Oct 2003 00:17:07 -0700 (PDT)

    What was the deal about the posting from the guy (on the freebsd lists)
    who kept losing his partition table?  Was that atapicam related too?

    We will be bringing in ATAng for the SATA and chipset support, but I
    intend to do it under a new driver name with a new major number.  I am
    not going to remove the old ATA driver (though they might end up being
    mutually exclusive).  I've learned the lesson from FreeBSD when Soren
    changed out ATA the first time and broke a lot of people, then did it
    again the second time with ATAng.  That isn't going to happen in
    DragonFly, hopefully.

					Matthew Dillon 

:> Actually, I'm not sure the comment about atapicam is strictly true: the
:> early revealed breakage involving atapicam had to do with API assumptions
:> that changed.  However, the vast majority of lasting breakage has been a
:> property of interrupt handling, and the nasty diversity of ATA hardware
:> which makes it difficult to test a driver change thoroughly without a
:> comprehensive effort involving literally hundreds (if not thousands) of
:> products :-(.
:Indeed. That is why the thought of doing it makes me cringe. My
:experience in storage, where "thou shalt not lose data", is that
:often most of the time is spent in testing. My hope is that, by having
:"safe" settings for previously unseen hardware, e.g. not enabling DMA or
:setting UDMA lower than the hardware claims is possible, much of the
:pain can be avoided. However, because of their low-end nature, there
:are many ATA devices that have idiosyncracies that can only be explained
:by poor testing on the part of the manufacturer.
:> The atapicam issues relating to ATAng in 5.x appear to be
:> entirely resolved now,
:That was my impression. What I was trying to say (I may suffer in my
:writing from implying broader generalizations than intended), is that from
:*briefly* skimming the results of a search of the archives for ATAng that
:the only major complaints that came in at the time were fundamental
:breakage of atapicam. I intended to imply that my impression of ATAng was
:that it is now, by and large, a stable subsytem.
:Thanks, I genuinely appreciate the information. I feel more comfortable
:knowing that an import would not be a "moving target".
:				-Kip

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