Re: blink driver power saving

On Wednesday 04 July 2007 18:11, Pavel Machek wrote:
Hi!

Perhaps one of you geniuses who all hate it can find a better way to
solve the "video output dead after kexec; but need visual feedback to the user
while crash dumping" problem. I'm waiting for your patches.


I don't don't like it ;) Unfortunately too many people end up enabling

Yes that's pretty weird. I admit I hadn't expected
that problem. blink is equivalent to "annoy me" and it
is a mystery why so many people should willingly ask their computer to
annoy them.

tristate "Keyboard blink driver"

...drivers are not expected to act on their own. I was expecting to
get nice /sys/class/led* interface to my keyboard leds.

BTW ... I still believe we should have /sys/class/led* interface to
those leds. I'd like to make them blink with hdd activity on some
machines... of course, that needs non-buggy KBC.

I'll take patches. Ofcourse we'll have to keep the current EV_LED interface
for compatibility.

Here's a working version. For some reason, it only works with capslock
led. (But so does your code, is that thinkpad problem?)


My code does blink NumLock on my box (Dell) so I wonder why it does not
on your box...

Anyway, as far as the patch goes - I don't think we want to do it this
way for a couple of reasons:

1. It does not reflect the true device hierarchy - LEDs are not children
of input devices, they are children of whatever device that owns input
device. So in case of AT keyboard LEDs should grow from corresponding
serio port, not input device and so atkbd should register all of its leds.

2. LEDs will stop working if input device is grabbed via EVIOCSGRAB.
I think that grab should not cross subsystem boundaries.

--
Dmitry
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