Re: [PATCH] libata: Handle bay devices in dock stations

[Holger Macht <hmacht@suse.de>]

On Fri 30. May - 13:07:39, tom@dbservice.com wrote:
> Quoting Holger Macht <hmacht@suse.de>:
>
>> * Differentiate between bay devices in dock stations and others:
>>
>>  - When an ACPI_NOTIFY_EJECT_REQUEST appears, just signal uevent to
>>    userspace (that is when the optional eject button on a bay device is
>>    pressed/pulled) giving the possibility to unmount file systems and to
>>    clean up. Also, only send uevent in case we get an EJECT_REQUEST
>>    without doing anything else. In other cases, you'll get an add/remove
>>    event because libata attaches/detaches the device.
>>
>>  - In case of a dock event, which in turn signals an
>>    ACPI_NOTIFY_EJECT_REQUEST, immediately detach the device, because it
>>    may already have been gone
>>
>> * In case of an ACPI_NOTIFY_DEVICE/BUS_CHECK, evaluate _STA to check if
>>   the device has been plugged or unplugged. If plugged, hotplug it, if
>>   unplugged, just signal event to userspace
>>   (initial patch by Matthew Garrett <mjg59@srcf.ucam.org>)
>>
>> * Call ACPI _EJ0 for detached devices
>
> Will this patch or the other bay/dock related patches you send in the past 
> days allow me to undock my laptop and still be able to suspend/resume 
> without locking the laptop up? And without having to run any userspace 
> scripts?
>
> My dock is not a simple port replicator, it has an USB hub and an ATA bay 
> in it. My tests showed that I need to 'echo 1 > /sys/.../scsi/.../eject' or 
> something like that before I can take the laptop out of the docking 
> station. If I don't do that and try to access the cdrom in the bay (or even 
> rescaning the scsi bus) after I have taken the laptop out of the dock it 
> results in a hard lockup. That in itself would not be a problem, because 
> it's just a simple command that I can do in an acpid script. But far worse 
> is that even if I do that, the computer locks up when I resume from 
> suspend. I run 2.6.24.7 which locks up every time I resume. In recent 
> versions from git it has somehow improved, there are situations where it 
> doesn't lock up, but there are still a few left where it does (I don't 
> remember the exact actions/commands I have to take).

Which kernel versions did you already try? But yes, those patches will
most likely help. But not sure about the resume issues...

Regards,
	Holger