Re: sata-sil drive detection issues.

[Mark Lord <kernel@teksavvy.com>]

On 11-02-24 02:04 PM, Mark Lord wrote:
> On 11-02-24 11:29 AM, Steven Haigh wrote:
>>
>> There is only one eSATA port on the back of the cradle. From looking at the
>> specs of the JMB352[1], it seems that it has the capability to have 3 SATA
>> channels. Two are used for the cradle bays, the third for the uplink to the PC.
>>
>> The PDF states:
>> "The SATA controller could be configured as host or device. The
>> 3-port SATA II 3.0G controllers further supports the eSATA to dual SATA
>> communication."
>>
>> [1] - http://www.jmicron.com/PDF/JMB352/JMB352.pdf
> 
> 
> It would be nice to know what that actually means.
> The only standard way for a single eSATA to connect to two SATA
> is via a SATA Port Multiplier.  I wonder if that chip implements one?

The product brief lists possible operation modes of the chip as:

 -- RAID0, RAID1, JBOD, or Port Multiplier

So I would guess that the drive detection issues must have something
to do with the operation mode.  I wonder how one selects *which* mode
should be used by the chip?

Or quite likely the only hardware mode is "Port Multiplier",
and the rest are just fakeraid things in software.

You and Tejun ought to be able to collect some debugging info
(eg. initial ATA register state on probe) to see if the device
even tries to report itself as a port multiplier.

Tricky stuff, undocumented hardware.