> -----Original Message----- > From: Peter Maydell <peter.mayd...@linaro.org> > Sent: 16 May 2022 10:57 > To: Frederic Konrad <fkon...@xilinx.com> > Cc: qemu-devel@nongnu.org; alist...@alistair23.me; > edgar.igles...@gmail.com; qemu-...@nongnu.org; Sai Pavan Boddu > <saip...@xilinx.com>; Edgar Iglesias <edg...@xilinx.com>; > fkon...@amd.com; Sai Pavan Boddu <saip...@xilinx.com>; Edgar Iglesias > <edg...@xilinx.com> > Subject: Re: [PATCH v1 2/4] xlnx_dp: Introduce a vblank signal > > On Tue, 3 May 2022 at 16:27, <frederic.kon...@xilinx.com> wrote: > > > > From: Sai Pavan Boddu <sai.pavan.bo...@xilinx.com> > > > > Add a periodic timer which raises vblank at a frequency of 30Hz. > > > > Signed-off-by: Sai Pavan Boddu <saip...@xilinx.com> > > Signed-off-by: Edgar E. Iglesias <edgar.igles...@xilinx.com> > > Changes by fkonrad: > > - Switched to transaction-based ptimer API. > > - Added the DP_INT_VBLNK_START macro. > > Signed-off-by: Frederic Konrad <fkon...@amd.com> > > --- > > > > @@ -1309,6 +1323,10 @@ static void xlnx_dp_realize(DeviceState *dev, > Error **errp) > > &as); > > AUD_set_volume_out(s->amixer_output_stream, 0, 255, 255); > > xlnx_dp_audio_activate(s); > > + s->vblank = ptimer_init(vblank_hit, s, PTIMER_POLICY_DEFAULT); > > + ptimer_transaction_begin(s->vblank); > > + ptimer_set_freq(s->vblank, 30); > > + ptimer_transaction_commit(s->vblank); > > The ptimer documentation (in include/hw/ptimer.h) says > * The default ptimer policy retains backward compatibility with the legacy > * timers. Custom policies are adjusting the default one. Consider providing > * a correct policy for your timer. > > and goes on to describe various weird behaviours of the default > policy. You almost certainly don't want to use PTIMER_POLICY_DEFAULT > for a new timer -- instead figure out the behaviour you actually > want and specify the appropriate flags.
Hi Peter, Thanks for your feedback. Yes, I think, I can just use CONTINUOUS_TRIGGER and NO_IMMEDIATE_TRIGGER instead of forcing the decrementer / reload value to 1. Would that be cleaner? Thanks, Fred > > thanks > -- PMM
