Date: Mon, 15 Dec 2014 01:22:11 -0800 From: =?utf-8?Q?Ask_Bj=C3=B8rn_Hansen?= <ask@develooper.com> To: Neel Natu <neelnatu@gmail.com> Cc: "freebsd-virtualization@freebsd.org" <freebsd-virtualization@freebsd.org> Subject: Re: Unsupported cmd:c4 (ada0:ahcich0:0:0:0): READ_MUL. ACB: c4 00 00 00 00 40 00 00 00 00 01 00 Message-ID: <9AF2F3EC-E54D-49D6-A9E0-AB3163CEFCB2@develooper.com> In-Reply-To: <CAFgRE9F5bC4t6sDRtKVRLD0kLeLFWi%2B1kK5Jx5c8RZHYh5LyUA@mail.gmail.com> References: <C47B8B4E-5127-4121-BC73-2B4E6129652B@develooper.com> <CAFgRE9F5bC4t6sDRtKVRLD0kLeLFWi%2B1kK5Jx5c8RZHYh5LyUA@mail.gmail.com>
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[ It looks like I didn't send this earlier ]
> Are you, by any chance, setting the tunable 'hw.ata.ata_dma' to 0 to
> disable DMA?
>=20
> I ask this because in the dmesg above you have:
> ada0: 300.000MB/s transfers (SATA 2.x, PIO4, PIO 8192bytes)
>=20
> In my setup, I get this instead:
> ada0: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes)
Hi Neel,
Good eyes, indeed I do! Very nice.
# grep -rh ata_dma .
echo 'hw.ata.ata_dma=3D"0"' >> boot/device.hints
My VCS log says I added it 6 years ago -- "disable DMA for better =
Soekris/Alix support=E2=80=9D, which probably seemed like a very =
specific commit message at the time. For what it's worth the system is =
booting fine without the setting on my alix and soekris boards, too.
Thank you!
The ZFS devmode didn't seem to make a difference for this; but setting =
it to 'dev' did fix some warnings I was getting when making snapshots, =
so that was useful too. Thank you, Allan.
Ask=
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