When upgrading K values of a LA1.0 print, also adjust E-jerk settings
(<2) if permissible according to current accell limits. The same is also
true when jerk is set mid-print via 'M205 E'.
Existing values are always restored when switching to another
compatibility mode.
TODO: Since this is stateful, we will need to save the current print
mode / acceleration and jerk in the eeprom for this to survive a power
panic (see prusa3d#2456).
When calculating the advance tick interval, be sure to check for integer
overflow. Very low step rates can result in values exceeding uint16_t
causing premature LA tick delivery.
An overflow resulting in zero would also block in an infinite loop
within advance_spread().
Even though such rates are worthless in terms of compensation and often
result in 0 extra ticks as well, do not disable LA for the block (as
doing so would reset the count for short segments) and do not check for
zero in multiple paces either.
Saturate the interval instead, delaying any further tick to the next
block.
M24 was always cleaning the last print failstats. But because M24 is
used to restore a print after power failure (by setting the seek
offset), it would also reset the stats incorrectly after resuming.
Check for the file index position and reset the stats only when a print
is started from the beginning of the file.
Apply the same logic to M32 and similarly handle the LA10->15 conversion
(do not re-apply the adjustment for a resumed print).
There is a chance that current_block can be NULL despite
the queue being non-empty. This can happen early after a block has been
queued, but before the isr has picked it up for processing, and/or when
the current block is at the last step and is being discarded.
Check for current_block directly to avoid this race.
Both during early init and in uvlo_tiny, display "POWER PANIC DETECTED"
if enough charge is left.
This is not worth doing in regular uvlo_, as we want to give full
priority to the X motor
If power has been lost during startup already a falling edge would be
skipped, causing the print to continue and lose its state without
being able to save again.
Check for a low line after arming the interrupt and simply wait
for reset.
Do not allow uvlo_tiny() to trigger before the previous print has
already been recovered.
A quick repeated power failure could cause uvlo_tiny to overwrite
the Z position before it has been correctly recovered.
enable/disable_z behave differently when PSU_Delta is defined.
During powerpanic and kill however we do *really* need to save energy
and poweroff the motors.
Rename enable/disable_z as poweron/poweroff_z and define some aliases so
that we can use the low-level function where needed.
