[Intel-gfx] [PATCH 1/6] drm/i915: Add support for DRRS in intel_dp_set_m_n
Rodrigo Vivi
rodrigo.vivi at gmail.com
Thu Feb 19 09:22:43 PST 2015
On Fri, Feb 13, 2015 at 2:02 AM, Ramalingam C <ramalingam.c at intel.com> wrote:
> Till Gen 7 we have two sets of M_N registers, but Gen 8 onwards
> we have only one M_N register set. To support DRRS on both scenarios
> a input parameter to intel_dp_set_m_n is added.
>
> In case of DRRS, When platform provides two set of M_N registers for dp,
> we can program them with two different dividers and switch between them.
> But when only one such register set is provided, we have to program
> the required divider M_N value on that registers itself.
>
> Two enum members M1_N1 and M2_N2 are defined to represent the above
> scenarios.
>
> M1_N1 : Program dp_m_n on M1_N1 registers
> dp_m2_n2 on M2_N2 registers (If supported)
>
> M2_N2 : Program dp_m2_n2 on M1_N1 registers
> M2_N2 registers are not supported
On a quickly first look this enum name confused me... "Why name M2_N2
when it isn't supported?!"
But than I remembered the logic behind, read again and saw it was
M2_N2 value on dp_m_n register...
>
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> ---
> drivers/gpu/drm/i915/intel_display.c | 30 +++++++++++++++++++++++-------
> drivers/gpu/drm/i915/intel_drv.h | 22 +++++++++++++++++++++-
> 2 files changed, 44 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 3b0fe9f..2af24a7 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4322,7 +4322,7 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
> intel_prepare_shared_dpll(intel_crtc);
>
> if (intel_crtc->config->has_dp_encoder)
> - intel_dp_set_m_n(intel_crtc);
> + intel_dp_set_m_n(intel_crtc, M1_N1);
>
> intel_set_pipe_timings(intel_crtc);
>
> @@ -4430,7 +4430,7 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
> intel_enable_shared_dpll(intel_crtc);
>
> if (intel_crtc->config->has_dp_encoder)
> - intel_dp_set_m_n(intel_crtc);
> + intel_dp_set_m_n(intel_crtc, M1_N1);
>
> intel_set_pipe_timings(intel_crtc);
>
> @@ -5044,7 +5044,7 @@ static void valleyview_crtc_enable(struct drm_crtc *crtc)
> }
>
> if (intel_crtc->config->has_dp_encoder)
> - intel_dp_set_m_n(intel_crtc);
> + intel_dp_set_m_n(intel_crtc, M1_N1);
>
> intel_set_pipe_timings(intel_crtc);
>
> @@ -5120,7 +5120,7 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc)
> i9xx_set_pll_dividers(intel_crtc);
>
> if (intel_crtc->config->has_dp_encoder)
> - intel_dp_set_m_n(intel_crtc);
> + intel_dp_set_m_n(intel_crtc, M1_N1);
>
> intel_set_pipe_timings(intel_crtc);
>
> @@ -5895,13 +5895,29 @@ static void intel_cpu_transcoder_set_m_n(struct intel_crtc *crtc,
> }
> }
>
> -void intel_dp_set_m_n(struct intel_crtc *crtc)
> +void intel_dp_set_m_n(struct intel_crtc *crtc, enum link_m_n_set m_n)
> {
> + struct intel_link_m_n *dp_m_n, *dp_m2_n2 = NULL;
> +
> + if (m_n == M1_N1) {
> + dp_m_n = &crtc->config->dp_m_n;
> + dp_m2_n2 = &crtc->config->dp_m2_n2;
> + } else if (m_n == M2_N2) {
> +
> + /*
> + * M2_N2 registers are not supported. Hence m2_n2 divider value
> + * needs to be programmed into M1_N1.
> + */
.. also this good comment refreshed my memory! ;)
> + dp_m_n = &crtc->config->dp_m2_n2;
> + } else {
> + DRM_ERROR("Unsupported divider value\n");
> + return;
> + }
> +
> if (crtc->config->has_pch_encoder)
> intel_pch_transcoder_set_m_n(crtc, &crtc->config->dp_m_n);
> else
> - intel_cpu_transcoder_set_m_n(crtc, &crtc->config->dp_m_n,
> - &crtc->config->dp_m2_n2);
> + intel_cpu_transcoder_set_m_n(crtc, dp_m_n, dp_m2_n2);
> }
>
> static void vlv_update_pll(struct intel_crtc *crtc,
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 1de8e20..1fb1529 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -593,6 +593,26 @@ struct intel_hdmi {
> struct intel_dp_mst_encoder;
> #define DP_MAX_DOWNSTREAM_PORTS 0x10
>
> +/*
> + * enum link_m_n_set:
> + * When platform provides two set of M_N registers for dp, we can
> + * program them and switch between them incase of DRRS.
> + * But When only one such register is provided, we have to program the
> + * required divider value on that registers itself based on the DRRS state.
> + *
> + * M1_N1 : Program dp_m_n on M1_N1 registers
> + * dp_m2_n2 on M2_N2 registers (If supported)
> + *
> + * M2_N2 : Program dp_m2_n2 on M1_N1 registers
> + * M2_N2 registers are not supported
> + */
> +
> +enum link_m_n_set {
> + /* Sets the m1_n1 and m2_n2 */
> + M1_N1 = 0,
> + M2_N2
> +};
> +
> struct intel_dp {
> uint32_t output_reg;
> uint32_t aux_ch_ctl_reg;
> @@ -994,7 +1014,7 @@ void hsw_enable_pc8(struct drm_i915_private *dev_priv);
> void hsw_disable_pc8(struct drm_i915_private *dev_priv);
> void intel_dp_get_m_n(struct intel_crtc *crtc,
> struct intel_crtc_state *pipe_config);
> -void intel_dp_set_m_n(struct intel_crtc *crtc);
> +void intel_dp_set_m_n(struct intel_crtc *crtc, enum link_m_n_set m_n);
> int intel_dotclock_calculate(int link_freq, const struct intel_link_m_n *m_n);
> void
> ironlake_check_encoder_dotclock(const struct intel_crtc_state *pipe_config,
> --
> 1.7.9.5
>
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Thanks for this change.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
--
Rodrigo Vivi
Blog: http://blog.vivi.eng.br
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