Re: ptimer use of bottom-half handlers

2019-10-04 Thread Richard Henderson
On 10/4/19 10:40 AM, Peter Maydell wrote: > So we should probably cause that to happen in the new scheme > (conceptually, something like "the trigger callback is > implicitly considered to be called from within a tx begin/ > commit block, so (a) it doesn't need to do begin/commit itself > and (b) i

Re: ptimer use of bottom-half handlers

2019-10-04 Thread Peter Maydell
On Fri, 27 Sep 2019 at 11:01, Peter Maydell wrote: > The ptimer API is basically a down-counter (with a lot of bells > and whistles), with functions to do things like "read current count" > and "write current count". When the counter hits zero it typically > reloads, and the ptimer code notifies a

Re: ptimer use of bottom-half handlers

2019-10-01 Thread Peter Maydell
On Fri, 27 Sep 2019 at 18:40, Richard Henderson wrote: > If "other things" are being changed along with ptimer_set_count, then is the > boolean result of ptimer_set_count necessarily still relevant after the "other > things"? > > Can we record the set of things to be done within a > ptimer_transac

Re: ptimer use of bottom-half handlers

2019-09-27 Thread Richard Henderson
On 9/27/19 3:01 AM, Peter Maydell wrote: > (2) call the device's callback function directly when the > ptimer triggers from the QEMU timer expiry. But for > the case of "a call to ptimer_set_count() etc caused > the timer to trigger", don't call the callback, instead > return a

ptimer use of bottom-half handlers

2019-09-27 Thread Peter Maydell
Investigating https://bugs.launchpad.net/qemu/+bug/177 I found what seems to be a design flaw in the ptimer code. The ptimer API is basically a down-counter (with a lot of bells and whistles), with functions to do things like "read current count" and "write current count". When the counter hit