ahci timeout during boot on a particular mobo

[Andriy Gapon]

On 19/08/2016 14:06, Alexander Motin wrote:
> On 19.08.16 11:30, Andriy Gapon wrote:
>> So, what's suspicious here is that we discover two AHCI channels on the JMicron
>> device and we seem to discover some sort of a device on one of them.  But the
>> communication with that (phantom?) device times out and that causes a very long
>> delay during the boot.
> 
> This fake device is the most interesting part.  Marvell AHCI RAID chips
> in such way expose RAID management device, but I doubt that JMicron is
> so advanced, at least it seems like not implemented properly enough.
> 
>> Is there a way to fix the boot delay?
>>
>> Searched for JMB361 in the source code, looked at some nearby device entries,
>> and - is it as simple as adding AHCI_Q_1CH quick for this device?
> 
> AHCI_Q_1CH quirk was added for early Marvell chips that were ever
> dirtier mix of legacy ATA and AHCI, that reported total number of ports
> instead of expected AHCI ones.  May be JMB361 is also like that, but I
> never had those check.  JMB362 I have does not have this problem,
> reporting two real SATA ports, even though it has one legacy PATA port
> also.  I don't have strong objections against this quirk.  I am not sure
> whether it is right solution, but suppose that in couple years nobody
> will bother about that hardware at all.
> 

Thank you for the reply!
I found this bit of info about JMB361
http://www.clubedohardware.com.br/datasheets/JMB361.pdf and it confirms that the
controller has a single SATA port.  And JMB362 has two ports
http://www.clubedohardware.com.br/datasheets/JMB361.pdf.
Maybe the second port on JMB361 has some sort of a SATA-to-IDE adapter and
perhaps it's that adapter that gets detected as a phantom device.

-- 
Andriy Gapon