> -----Original Message-----
> From: Deak, Imre <imre.deak@xxxxxxxxx>
> Sent: Friday, December 15, 2023 11:02 AM
> To: Kahola, Mika <mika.kahola@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] drm/i915/display: C20 clock state verification
>
> On Fri, Dec 15, 2023 at 10:53:36AM +0200, Imre Deak wrote:
> > On Fri, Dec 15, 2023 at 10:00:57AM +0200, Mika Kahola wrote:
> > > Add clock state verification for C20. Since we are usign either A or
> > > B contexts, which are selected based on clock rate, we first need to
> > > calculate hw clock and use that clock to select which context we are
> > > using.
> >
> > Could the description be clearer that the patch _fixes_ the context
> > selection? (Also the subject line should always say _what_ the patch
> > does.)
OK, should I add the fixes tag as well? I will reword the commit message to better describe what's going on in this patch.
> >
> > >
> > > Signed-off-by: Mika Kahola <mika.kahola@xxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_cx0_phy.c | 8 +++++++-
> > > 1 file changed, 7 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> > > b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> > > index 775c1c4a8978..6757e9f941e4 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> > > @@ -3079,8 +3079,9 @@ static void intel_c20pll_state_verify(const struct intel_crtc_state *state,
> > > const struct intel_c20pll_state *mpll_sw_state = &state->cx0pll_state.c20;
> > > bool use_mplla;
> > > int i;
> > > + int hw_clock = intel_c20pll_calc_port_clock(encoder,
> > > +mpll_hw_state);
> > >
> > > - use_mplla = intel_c20_use_mplla(mpll_hw_state->clock);
> > > + use_mplla = intel_c20_use_mplla(hw_clock);
> >
> > It's mpll_hw_state->tx[0] C20_PHY_USE_MPLLB which tells the HW which
> > context to use, so I think it's better to use the same condition here.
Maybe I will ditch the use_mplla completely and go directly with
if (mpll_hw_state->tx]0] & C20_PHY_USE_MPLLB) { .. }
instead?
>
> You could also add a check intel_c20_use_mplla(clock) matches the above flag.
>
> >
> > > if (use_mplla) {
> > > for (i = 0; i < ARRAY_SIZE(mpll_sw_state->mplla); i++) {
> > > I915_STATE_WARN(i915, mpll_hw_state->mplla[i] !=
> > > mpll_sw_state->mplla[i], @@ -3110,6 +3111,11 @@ static void intel_c20pll_state_verify(const struct intel_crtc_state *state,
> > > crtc->base.base.id, crtc->base.name, i,
> > > mpll_sw_state->cmn[i], mpll_hw_state->cmn[i]);
> > > }
> > > +
> > > + I915_STATE_WARN(i915, hw_clock != mpll_sw_state->clock,
> > > + "[CRTC:%d:%s] mismatch in C20: Register CLOCK (expected %d, found %d)",
> > > + crtc->base.base.id, crtc->base.name,
> > > + mpll_sw_state->clock, hw_clock);
> >
> > I think the intel_crtc_state::port_clock SW/HW state verification is
> > equivalent to the above, but it's good to verify it here as well. I
> > would store hw_clock to mpll_hw_state->clock in
> > intel_c20pll_readout_hw_state() though.
Well, clock is part of pll structure anyway, so it might as well be checked here too.
I will store hw clock too in intel_c20pll_readout_hw_state()
Thanks!
Mika
> >
> > > }
> > >
> > > void intel_cx0pll_state_verify(struct intel_atomic_state *state,
> > > --
> > > 2.34.1
> > >
