[Intel-gfx] [PATCH CI] drm/i915/display/tgl: Do not program clockgating
Jani Nikula
jani.nikula at intel.com
Wed Dec 4 07:31:33 UTC 2019
On Tue, 03 Dec 2019, "Souza, Jose" <jose.souza at intel.com> wrote:
> On Tue, 2019-12-03 at 10:20 +0200, Jani Nikula wrote:
>> On Mon, 02 Dec 2019, José Roberto de Souza <jose.souza at intel.com>
>> wrote:
>> > Talked with HW team and this is a left over, driver should not
>> > program clockgating, dekel firmware will be reponsible for any
>> > clockgating programing.
>> >
>> > v2:
>> > Added WARN_ON
>> >
>> > BSpec issue: 20885
>> > BSpec: 49292
>> >
>> > Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>> > Cc: Matt Roper <matthew.d.roper at intel.com>
>> > Cc: Jani Nikula <jani.nikula at intel.com>
>> > Reviewed-by: Matt Roper <matthew.d.roper at intel.com>
>> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
>> > ---
>> > drivers/gpu/drm/i915/display/intel_ddi.c | 54 +++++++-------------
>> > ----
>> > 1 file changed, 15 insertions(+), 39 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
>> > b/drivers/gpu/drm/i915/display/intel_ddi.c
>> > index a976606d21c7..66052a9f1474 100644
>> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
>> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
>> > @@ -3167,6 +3167,10 @@ icl_phy_set_clock_gating(struct
>> > intel_digital_port *dig_port, bool enable)
>> > u32 val, bits;
>> > int ln;
>> >
>> > + /* See "PHY Clockgating programming" note */
>>
>> Where?
>
> BSpec: 49292, PHY Clockgating programming: Display driver should not
> program the following bits.
In a code comment, people would look for the note in the source. That's
certainly what *I* did. And it's pretty rude to have a reference to
internal documentation in a public source tree.
If you think we need to have the comment, please paraphrase the
spec. For example, just "Per Bspec we shouldn't do this on gen12+" or
something is better than an obscure reference.
BR,
Jani.
>
>>
>> > + if (WARN_ON(INTEL_GEN(dev_priv) >= 12))
>> > + return;
>> > +
>> > if (tc_port == PORT_TC_NONE)
>> > return;
>> >
>> > @@ -3175,39 +3179,26 @@ icl_phy_set_clock_gating(struct
>> > intel_digital_port *dig_port, bool enable)
>> > MG_DP_MODE_CFG_GAONPWR_GATING;
>> >
>> > for (ln = 0; ln < 2; ln++) {
>> > - if (INTEL_GEN(dev_priv) >= 12) {
>> > - I915_WRITE(HIP_INDEX_REG(tc_port),
>> > HIP_INDEX_VAL(tc_port, ln));
>> > - val = I915_READ(DKL_DP_MODE(tc_port));
>> > - } else {
>> > - val = I915_READ(MG_DP_MODE(ln, tc_port));
>> > - }
>> > + val = I915_READ(MG_DP_MODE(ln, tc_port));
>> >
>> > if (enable)
>> > val |= bits;
>> > else
>> > val &= ~bits;
>> >
>> > - if (INTEL_GEN(dev_priv) >= 12)
>> > - I915_WRITE(DKL_DP_MODE(tc_port), val);
>> > - else
>> > - I915_WRITE(MG_DP_MODE(ln, tc_port), val);
>> > + I915_WRITE(MG_DP_MODE(ln, tc_port), val);
>> > }
>> >
>> > - if (INTEL_GEN(dev_priv) == 11) {
>> > - bits = MG_MISC_SUS0_CFG_TR2PWR_GATING |
>> > - MG_MISC_SUS0_CFG_CL2PWR_GATING |
>> > - MG_MISC_SUS0_CFG_GAONPWR_GATING |
>> > - MG_MISC_SUS0_CFG_TRPWR_GATING |
>> > - MG_MISC_SUS0_CFG_CL1PWR_GATING |
>> > - MG_MISC_SUS0_CFG_DGPWR_GATING;
>> > + bits = MG_MISC_SUS0_CFG_TR2PWR_GATING |
>> > MG_MISC_SUS0_CFG_CL2PWR_GATING |
>> > + MG_MISC_SUS0_CFG_GAONPWR_GATING |
>> > MG_MISC_SUS0_CFG_TRPWR_GATING |
>> > + MG_MISC_SUS0_CFG_CL1PWR_GATING |
>> > MG_MISC_SUS0_CFG_DGPWR_GATING;
>> >
>> > - val = I915_READ(MG_MISC_SUS0(tc_port));
>> > - if (enable)
>> > - val |= (bits |
>> > MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE(3));
>> > - else
>> > - val &= ~(bits |
>> > MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE_MASK);
>> > - I915_WRITE(MG_MISC_SUS0(tc_port), val);
>> > - }
>> > + val = I915_READ(MG_MISC_SUS0(tc_port));
>> > + if (enable)
>> > + val |= (bits | MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE(3));
>> > + else
>> > + val &= ~(bits |
>> > MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE_MASK);
>> > + I915_WRITE(MG_MISC_SUS0(tc_port), val);
>> > }
>> >
>> > static void
>> > @@ -3508,12 +3499,6 @@ static void tgl_ddi_pre_enable_dp(struct
>> > intel_encoder *encoder,
>> > * down this function.
>> > */
>> >
>> > - /*
>> > - * 7.d Type C with DP alternate or fixed/legacy/static
>> > connection -
>> > - * Disable PHY clock gating per Type-C DDI Buffer page
>> > - */
>> > - icl_phy_set_clock_gating(dig_port, false);
>> > -
>> > /* 7.e Configure voltage swing and related IO settings */
>> > tgl_ddi_vswing_sequence(encoder, crtc_state->port_clock, level,
>> > encoder->type);
>> > @@ -3565,15 +3550,6 @@ static void tgl_ddi_pre_enable_dp(struct
>> > intel_encoder *encoder,
>> > if (!is_trans_port_sync_mode(crtc_state))
>> > intel_dp_stop_link_train(intel_dp);
>> >
>> > - /*
>> > - * TODO: enable clock gating
>> > - *
>> > - * It is not written in DP enabling sequence but "PHY
>> > Clockgating
>> > - * programming" states that clock gating should be enabled
>> > after the
>> > - * link training but doing so causes all the following
>> > trainings to fail
>> > - * so not enabling it for now.
>> > - */
>> > -
>> > /* 7.l Configure and enable FEC if needed */
>> > intel_ddi_enable_fec(encoder, crtc_state);
>> > intel_dsc_enable(encoder, crtc_state);
--
Jani Nikula, Intel Open Source Graphics Center
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