The device will always use sequence number 0 for certain messages. We
use this knowledge to filter the messages and assume that it is one of
these special messages rather than a response to a command.
However, we could end up sending a command with a sequence counter of 0
which would result in the response being ignored. Fix this by ensuring
we correctly wrap from 255 to 1 instead of 0.
Fixes: #358
Some OEM will integrate fingerprint device with powerButton. It's
possible that a user may press the power button during fingerprint
enroll or identify. This would lead to unintended PC shutdown or
hibernation. We add pwr_btn_shield cmd and related process to shield
the power button function when the fingerprint functionality (enroll and
identify) is used and restore power button function afterwards.
We may want to be able to talk with the device while it's closed to
queue commands to be performed once it opens (could be even a script),
so to do this we need to close the device first, send those commands and
eventually process them.
We used a trick to send an invalid command before that was ignored by
release, but having the device available is just easier to handle.
So, when keep alive is enabled we don't stop the listener when closing
but only on actual device disposition.
The idea of the test was just checking what happens when we're opening a
device multiple times while a first request is still going.
However, it actually ends up also checking the previous commit change
because without it we'd stop the close iteration before the device is
actually closed and stop the open iteration before the device is
actually opened, leading to an infinite loop.
We're delaying any completed operation until we've completed an idle,
but the open/close state is changed and notified as soon as the device
completes the operation.
While this can be true, it means that we notify earlier than the finish
callback is actually called, while iterations are still needed to get
the actual state completed, and the current_task reset.
So if we'd open/close and iterate till fp_device_is_open() returns TRUE
we'd end up in a state in which the device is marked as ready, but it's
actually still busy since it's priv->current_task isn't unset yet.
The same if we'd try to do any action on notify::opened.
In case we do an early error return in verify and identify calls we
do not initialize the task data, but still in the finish functions we
still try to use it.
Avoid doing this, but just nullify the returned values.
When opening the device we can process commands that we left for that
after the previous close, to do that we only have to inject an invalid
command that will be processed (and ignored) while closing, so that at
next device opening we will be able to proceed with the previously
sent commands.
Add tests to finally check this case!
Each command should be separated by SLEEP to be considered as something
we want to perform during the current operation, otherwise will be used
by next operation consuming it.
In case we sent a sleep event to the device we may want to wait it to
emit the finger needed state before the timeout is completed.
So add a function to manage this for all the scan cases
The irq handler may already be stopped if stop_irq_handler is called. In
that case, we should immediately call the handler rather than just never
calling it.
This fixes deactivation when the device is unexpectedly unplugged.
Closes: #355
