Re: AHCI problem with hotplug

[Tony Battersby <tonyb@cybernetics.com>]

Tejun Heo wrote:
> Tony Battersby wrote:
>   
>> I am having a problem getting Linux to detect hot-plugged SATA disks on my
>> ICH7 AHCI controller (SuperMicro PDSME motherboard).  On any SATA port that
>> already had a disk plugged in during BIOS POST, Linux will see the disk and
>> detect hot-plug and hot-unplug events just fine.  On any SATA port that did
>> not have a disk plugged in during BIOS POST, Linux will not see a disk no
>> matter what.  Here are the different sequences of events that I have tried:
>>
>> 1) boot with SATA disk plugged in
>>    modprobe ahci: disk detected
>>    unplug disk:   disk deleted
>>    plug in disk:  disk detected
>>
>> 2) boot with SATA disk plugged in
>>    unplug disk
>>    modprobe ahci
>>    plug in disk: disk detected
>>    unplug disk:  disk deleted
>>    plug in disk: disk detected
>>    unplug disk:  disk deleted
>>    plug in disk to any other SATA port    -> not detected
>>    plug in disk to the original SATA port -> disk detected
>>
>> 3) boot with SATA disk unplugged
>>    plug in disk to any SATA port
>>    modprobe ahci: not detected
>>    grep ahci /proc/interrupts: 0 interrupts
>>
>> 4) boot with SATA disk unplugged
>>    modprobe ahci
>>    plug in disk to any SATA port: not detected
>>    grep ahci /proc/interrupts: 0 interrupts
>>
>> 5) keep SATA disk plugged in during BIOS POST but unplug it before the
>>    kernel boots
>>    kernel hangs at "BIOS data check"
>>
>> I have tried both 2.6.24.7 and 2.6.27.8 with the same result.
>>
>> The BIOS is configured as follows:
>> Parallel ATA:         [Enabled]
>> Serial ATA:           [Enabled]
>> SATA Controller Mode: [Enhanced]
>> SATA RAID:            [Disabled]
>> SATA AHCI:            [Enabled]
>>
>> The root filesystem is on a parallel IDE disk using the legacy (non-libata)
>> piix driver.
>>     
>
> The BIOS could be tristating the ports.  Does it work if you issue
> manual rescan (echo - - - > /sys/class/scsi_host/hostN/scan)?
>
>   
No luck.  I get:

ata1: hard resetting link
ata1: SATA link down (SStatus 0 SControl 0)
ata1: EH complete

And the drive isn't seen.

Tony