02.07.2015 21:09, Peter Maydell пишет:
On 2 July 2015 at 18:52, Dmitry Osipenko <dig...@gmail.com> wrote:
02.07.2015 20:34, Peter Maydell пишет:
This will now cause us to do the "reload the timer"
logic if you write a 1 to the control bit when it was
already 1, which we didn't do before.
The logic I suggested in my previous review
comment gets this right...
-- PMM
The problem with code you suggested is that won't start periodic count after
one-shot tick was completed.
Can you give more detail? This code is only for when
the guest writes to the control register, so it doesn't
get run when a one-shot tick completes.
In any case, the code currently in master does:
old value new value action
0 0 nothing
0 1 reload timer
1 0 nothing
1 1 nothing
Your first patch did:
old value new value action
0 0 delete timer
0 1 reload timer
1 0 delete timer
1 1 nothing
Your second patch does:
old value new value action
0 0 nothing
0 1 reload timer
1 0 delete timer
1 1 reload timer
My suggestion was:
old value new value action
0 0 nothing
0 1 reload timer
1 0 delete timer
1 1 nothing
If you think that's wrong, then surely your first
patch also has the same problem?
thanks
-- PMM
Yes, my first patch has same problem. Noticed that issue couple hours ago, it's
separate bug as I see now... Will make patch for it too.
To clarify new issue:
1) load TIMER_LOAD with some value
2) write (TIMER_CONTROL_ENABLE | TIMER_CONTROL_ONESHOT |
TIMER_CONTROL_IT_ENABLE) to TIMER_CONTROL
3) wait for one-shot complete
4) re-load TIMER_LOAD
5) write (TIMER_CONTROL_ENABLE | TIMER_CONTROL_PERIODIC |
TIMER_CONTROL_IT_ENABLE) to TIMER_CONTROL <---- it won't start, bug
Oh, and just noticed that timer code doesn't handle IT(interrupt enable) bit.
Will fix it too.
--
Dmitry
