Re: AHCI support Port Multiplier problem.

[Tejun Heo <tj@kernel.org>]

Hello,

On Fri, Jan 07, 2011 at 10:55:14AM +0800, Luo Dislo wrote:
> I am using AHCI driver, when CONFIG_SATA_PMP is set and the ahci
> driver DOES NOT have AHCI_HFLAG_NO_PMP. Libata sends Software Reset
> with PMP=0xF, trying to detect if Port Multiplier connected to the
> port. Unfortunately, if I plugged in general Hard drive, my
> controller failed to identify the hard drive.
> 
> What I observed was that libata always sent Software Reset with
> PMP=0xF and I guessed expecting signature is 0x96690101. I think
> libata should give up if the device does not return the Port
> Multiplier signature at the first time and take the signature value
> from device as the real device connnecting to the port now.
>
> What we said "support" PMP does not mean the port can only connnect
> to Port Multiplier. It might connect with hard drive or ATAPI
> device.

Which controller is this?  Can you please post the output of "lspci
-nn"?  SB600 had this problem and needed workaround but later SBs
fixed it.  Looks like someone else screwed up similarly.

Thanks.

-- 
tejun