Re: sata_mv port lockup on hotplug (kernel 2.6.38.2)

From: Mark Lord
Date: Tue Apr 26 2011 - 14:27:42 EST


On 11-04-25 07:30 AM, Tejun Heo wrote:
> On Mon, Apr 25, 2011 at 12:07:04PM +0100, Bruce Stenning wrote:
>> Tejun, what does it mean to limit a sata link to UDMA/100? I thought that this
>> was only for ata devices, and sata devices have the choice of 1.5Gbps, 3Gbps,
>> or 6 Gbps. Is that a false assumption? Is it related to early sata devices that
>> were still somewhat based on parallel ata designs?
>
> Yeap, devices behind SATA-PATA bridge were still affected by the
> transfer mode so libata tries to slow them down too along with link
> speed when limiting speed due to errors. Shouldn't affect native SATA
> devices.


Yeah, what he said. :)

First generation SATA devices were merely PATA transports
with a SATA-to-PATA converter chip onboard. Some of those
require that we set the transfer modes.

Ditto for various more modern setups, where CF-cards, PATA drives,
and other weirdos are connected through a discrete SATA bridge device.

Cheers
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