atkbd: fix first keystroke force reset

[aokblast]

Summary

The Framework Laptop EC debug console shows the keyboard force reset
when the first keystroke interrupt reached.

It is because the return value of probe_keyboard is non zero from the
echo test so that the kernel consider the keyboard is unconfigured.

So that when the keyboard interrupt is reached at the first time, it try
to reset then configure the keyboard.

Co-Authored-By: obiwac
Sponsored By: FreeBSD Foundation

[aokblast]

See: https://github.com/FrameworkComputer/EmbeddedController/blob/fwk-hx20-hx30-4410/common/keyboard_8042.c#L668

[aokblast]

Fix indent

[emaste]

sys/dev/atkbdc/atkbd.c

1260–1271

Could this introduce a regression on other systems? I found

Every byte sent to the keyboard gets a response of 0xFA ("acknowledge") from the keyboard.
The only exceptions to this are the keyboard's response to the "Resend" and "Echo" commands

should we do something like

int data;

data = read_kbd_data(kbdc);
if (data == KBD_ACK)
        data = read_kbd_data(kbdc);
if (data != KBD_ECHO) {
        empty_both_buffers(...

[wulf]

Should we cache read_kbd_data() rather than reread it?

[aokblast]

Be compatible for correct behavior

[aokblast]

In D50498#1152600, @wulf wrote:

Should we cache read_kbd_data() rather than reread it?

What do you mean on the cache? I thought read keyboard data is deque from some where or read from the bus. So reread will cause the different value.

sys/dev/atkbdc/atkbd.c

1260–1271

Yes, I look at the AT keyboard manual and it also has the narration. Fix it. Also, Maybe the chromebook is also the same problem but I don't have one to check.

[aokblast]

@wulf Are you still have concern on the read_kbd_data? If not, I plan to create the patch for merging.

[wulf]

In D50498#1153913, @aokblast wrote:

@wulf Are you still have concern on the read_kbd_data? If not, I plan to create the patch for merging.

Go forward if this patch fixes something for you. And you wrote that it really fixes

[aokblast]

OK. Patch for merging. Thanks! https://github.com/aokblast/freebsd-src/commit/f9f28b3ae3f64b2184058dda84be5da50258eb26

[jrtc27]

sys/dev/atkbdc/atkbd.c

1252