Re: [Qemu-devel] [PATCH] ps2: add support of auto-repeat

[Amos Kong]

On Thu, May 16, 2013 at 03:13:10PM +0800, li guang wrote:
> 在 2013-05-16四的 14:58 +0800，Amos Kong写道：
> > On Thu, May 16, 2013 at 01:30:28PM +0800, li guang wrote:
> > > 在 2013-05-16四的 12:30 +0800，Amos Kong写道：
> > > > Guest driver sets repeat rate and delay time by KBD_CMD_SET_RATE,
> > > > but ps2 backend doesn't process it and no auto-repeat implementation.
> > > > This patch adds support of auto-repeat feature.
> > > > 
> > > > Guest ps2 driver sets autorepeat to fastest possible in reset,
> > > > period: 250ms, delay: 33ms
> > > > 
> > > > Tested by 'sendkey' monitor command.
> > > > 
> > > > referenced: http://www.computer-engineering.org/ps2keyboard/
> > > > 
> > > > Signed-off-by: Amos Kong <address@hidden>

> > Hi, Li guang
> >  
> > > theoretically, we have to check if the typematic key is in break
> > > now, if so, we will not do repeat anymore.
> > 
> > You mean key is released?  I checked by '~keycode & 0x80', stop repeat
> > when key is release.
> > 
> > > don't you think we have a chance that new key can come in during
> > > waiting?
> > 
> > When the new key (press) comes, repeat_timer will be modified by
> > qemu_mod_timer(), original repate will be end.
> >  
> > > > +    if (auto_repeat) {
> > > > +        qemu_mod_timer(repeat_timer, qemu_get_clock_ns(vm_clock) +
> > > > +                       muldiv64(get_ticks_per_sec(), s->repeat_period,
> > > > +                       1000));
> > > > +        ps2_queue(&s->common, s->repeat_key);
> > > > +    }
> > > > +}
> > > > +
> > > > +
> > > >  /*
> > > >     keycode is expressed as follow:
> > > >     bit 7    - 0 key pressed, 1 = key released
> > > > @@ -167,7 +186,17 @@ static void ps2_put_keycode(void *opaque, int 
> > > > keycode)
> > > >              keycode = ps2_raw_keycode_set3[keycode & 0x7f];
> > > >          }
> > > >        }
> > > > +
> > > > +    /* only auto-repeat press event */
> > > > +    auto_repeat = ~keycode & 0x80;
> > 
> > ^^^
> 
> case:
> 
> 1. new key pressed
> 2. enter ps2_put_keycode
> 3. previous timer timeout

I guess it's repeat_timer

> 4. enter repeat_ps2_queue
> 5. put previous keycode in queue
> 6. back to ps2_put_keycode

back? repeat_ps_queue() is called in background.

> 7. check auto_repeat
> 
> so, an obsolete key comes up.
> can timer interrupt ps2_put_keycode?
 
no.

-- 
                        Amos.