Matthew Garrett wrote:
Modern laptops with hotswap bays still tend to utilise a PATA interface
on a SATA bridge, generally with the host controller in some legacy
emulation mode rather than AHCI. This means that the existing hotplug
code in libata is unable to work. The ACPI specification states that
these devices can send notifications when hotswapped, which avoids the
need to obtain notification from the controller. This patch uses the
existing libata-acpi code and simply registers a notification in order
to trigger a rescan whenever the firmware signals an event.
Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
---
Testing on an HP with the hotplug device as the slave on a PATA channel
flagged a bug - the notification needs to be tied to the channel handle
as well as the device ones. With this version, I can happily hotswap the
HP device. It ends up sitting for a few seconds while failing to
revalidate, but then recovers with everything working fine.
the code looks correct. I have one main reservation.
how can we be sure that this is active only where other hand-programmed
hotplug code is absent?
ACPI doesn't inherently know which of our controllers are already set up
to do hotplug, so it seems like there is a possibility of conflict if
both the firmware and the controller are chirping.
If we can quell my fears in that area, I'm ok with the change.
Jeff
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