Re: [Qemu-devel] [PATCH] monitor: intervally send down events to guest in hold time

[Paolo Bonzini <pbonzini@redhat.com>]

Il 22/04/2013 10:09, Amos Kong ha scritto:
> On Mon, Apr 22, 2013 at 03:32:52PM +0800, Amos Kong wrote:
>> On Sat, Apr 20, 2013 at 10:06:28AM -0600, Eric Blake wrote:
>>> On 04/18/2013 10:44 PM, Amos Kong wrote:
>>>> (qemu) sendkey a 1000
>>>>
>>>> Current design is that qemu only send one down event to guest,
>>>> and delay sometime, then send one up event. In this case, only
>>>> key can be identified by guest.
>>>>
>>>> This patch changed qemu to intervally send down events to guest
>>>> in the hold time, the interval is 100ms.
>>>
>>> I don't like this.
>>
>>> When you hold a key for a long time on bare metal,
>>> there is only one down and one up event;
>>
>> Really? I do check events by 'showkey', the output of showkey is not the
>> events sent from keyboard?
>>
>> # showkey -s (show keys' scancode)
>> I can always see many down scancodes, and one up scancode.
>> It's same when I disable / enable auto-repeat mode in system.
>>
>> In the real host / vnc guest/ sdl guest, hold one key, many down
>> events can be checked by showkey.
>  
> # watch cat /proc/interrupts
>           CPU0       CPU1       CPU2       CPU3
>  1:       1692      40309       1462       1795   IO-APIC-edge  i8042
> 
> hit a botton without long-time holding, interrupt count increased 2.
> hit a botton with long-time holding, interrupt count increased a lot (more than 2)

You're right.  The typematic delay/rate is implemented within the i8042
keyboard microcontroller (QEMU does not implement that register).

It is possible that software ignores interrupts for a key that is
already down, and reimplements autorepeat in software, but your patch is
correct.

Paolo