Re: keyboard issues
Hi Michael,
2018-09-05 3:01 GMT+02:00 Michael Schmitz <schmitzmic@gmail.com>:
>> on my Falcon i have the problem that under heavy load (like apt update)
>> moving the mouse often causes a key "hang" and repeat. Pressing
>> the space bar stops the repeating of the hanging key.
>
>
> Keyboard interrupts can be locked out for long enough for the driver to miss
> data. Apparently that does include crucial break codes.
>
> Do you see any 'keyboard overrun' messages in the console logs?
>
>> On an Atari, the mouse is connected to the keyboard, and produces
>> keyboard-like events. Moving a mousewheel is same as cursor up/down,
>> for example. I guess that the buffer overflows when CPU is occupied.
>>
>> If someone has an idea how to prevent that, i'd be thankful.
>> But then, its not a showstopping issue. A 100& used CPU will probably
>> just fail to fetch the IKBD buffer in time.
>
>
> The keyboard driver already tries to resynchronize the packet stream if it
> missed packets. Maybe we also need to synthesize a break code if the last
> key event sent to the input layer was a make code. Look at the state machine
> in arch/m68k/atari/atakeyb.c - line 163 says to skip this byte which is
> certainly necessary, but maybe additionally you want to check whether the
> previous keyboard state was KEYBOARD, and the break_flag was clear, and send
> out an input event for the previous scancode as key up event in that case .
> Need to keep track of the previous scancode though, and it won't protect you
> from key repeats when multiple keys were recorded as down at the time the
> overrun happens.
>
I tried to fix this key stuck effect in FreeMiNT's keyboard driver but
I failed :-/, in this link you have some information about my attempt:
https://github.com/freemint/freemint/issues/87
I'm a bit sceptic that this can be fixed in the keyboard driver, but
may be I'm wrong and I missed something. What it could be done is a
workaround in the drivers that are disabling the interrupts for a long
time, this workaround is a clever solution done in the drivers for the
Lightning VME an USB card for the TT, MiNT's NetUSBee driver copied
that workaround. It's all in the link above.
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