Re: libata hotplug question

[Tejun Heo <tj@kernel.org>]

Hello,

On 11/30/2009 03:04 PM, Benjamin Herrenschmidt wrote:
> Now, for libata, I haven't totally figured out what to do though.
> 
> It seems like when the state "changes", I can do something like ahci and
> call ata_ehi_hotplugged() followed by something like ata_port_freeze()
> to kick the EH... at least that's my rough understanding.

Yeap, that should be enough.

> But I don't quite get how to inform libata that the part has or has not
> something plugged in it. I thought about playing with the probe_mask but
> it looks like ata_eh_link_autopsy() will reset that since I'm PATA, not
> SATA and thus have no sata_scr_read()...

No, it won't reset the mask.  It will only reset if SCR read failed
with errors other than -EOPNOTSUPP.  If your driver isn't implementing
SCR access, it will fail with -EOPNOTSUPP.  Also, if SCR access fails,
autopsy dosen't clear probe_mask, it sets all bits there forcing
recovery part to full probing.

Anyways, setting probe_mask (if you don't know which is gone, setting
all bits works fine) and calling ata_port_freeze() is enough.  The
actual hot plug/unlpug path is the same as boot probing path, so
there's nothing more to do there.

Thanks.

-- 
tejun