DragonFly BSD
DragonFly users List (threaded) for 2005-03
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Re: ATA anomaly Question

From: Bill Hacker <wbh@xxxxxxxxxxxxx>
Date: Sun, 20 Mar 2005 03:31:28 +0800

Matthew Dillon wrote:

:Testing various PATA & SATA controllers under DragonFlyBSD 1.1 STABLE of :15 March:
:- Anomalies:
:Add-on controllers, SATA:
:- booting may report in dmesg: 'DMA limited to UDMA 33, non-ATA66 cable :or device'
:None of the SATA controllers under test have PATA ports.

   Just ignore it.  It's because our ATA driver isn't really all that
   SATA-aware, so it is doing certain ATA checks that don't apply to
   SATA.  The SATA controller ignores it.

Fine with me - so long as it doesn't actually downshift I/O rate-wise. (which IIRC, the FreeBSD ones actually *did* do, at least early-on. Ancient history now...)

:Same message can also occur with actual PATA controllers when the cable :is a proper UDMA-100,'
:and can do so erratically when different 'race' of UDMA-100 drives are :on same cables as Master/Slave.

Typically the cable is reversed (motherboard side is connected to the
drive and the drive side is connected to the motherboard) when the
message occurs for a standard PATA drive and the cable is UDMA-capable.
Matthew Dillon <dillon@xxxxxxxxxxxxx>

Most sockets & headets are keyed (blocked pin position) to prevent that (at least on the better cables I try to use). Ground leads 'float' at one end, are collected at the other end, IIRC.

Message doesn't (usually) occur in MB POST, BTW - only OS boot,
which is why I mentioned it.  Mixing older IBM/Hitachi masters
with newer Western Digital slaves can also cause it, even with
good cables, and on FreeBSD 4.10/11.

Was wondering if ACPI would get the same info from
a MB BIOS with HDD type set to 'AUTO' as from one
where the IDE discovery was done manually, then results
locked-in to the MB BIOS.

Not sure ACPI is even involved here, so the answer is
probably 'depends on the BIOS & ACPI compliance'.

Still testing....



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