> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Imre Deak
> Sent: Thursday, July 28, 2022 1:45 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: [PATCH v2 1/2] drm/i915/d12+: Disable DMC handlers during
> loading/disabling the firmware
>
> Disable the DMC event handlers before loading the firmware and after uninitializing
> the display, to make sure the firmware is inactive. This matches the Bspec
> "Sequences for Display C5 and C6" page for GEN12+.
>
> Add a TODO comment for doing the same on pre-GEN12 platforms.
>
> v2:
> - Add a macro for the number of event handlers.
> - Disable the event handlers only on GEN12+.
> - s/dev_priv/i915/ in docbook comment.
Looks Good to me.
Reviewed-by: Uma Shankar <uma.shankar@xxxxxxxxx>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> .../drm/i915/display/intel_display_power.c | 3 +
> drivers/gpu/drm/i915/display/intel_dmc.c | 56 +++++++++++++++++--
> drivers/gpu/drm/i915/display/intel_dmc.h | 1 +
> drivers/gpu/drm/i915/display/intel_dmc_regs.h | 2 +
> 4 files changed, 56 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> b/drivers/gpu/drm/i915/display/intel_display_power.c
> index 589af257edebc..22f65a9968c6a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -1433,6 +1433,7 @@ static void skl_display_core_uninit(struct
> drm_i915_private *dev_priv)
> return;
>
> gen9_disable_dc_states(dev_priv);
> + /* TODO: disable DMC program */
>
> gen9_dbuf_disable(dev_priv);
>
> @@ -1500,6 +1501,7 @@ static void bxt_display_core_uninit(struct
> drm_i915_private *dev_priv)
> return;
>
> gen9_disable_dc_states(dev_priv);
> + /* TODO: disable DMC program */
>
> gen9_dbuf_disable(dev_priv);
>
> @@ -1675,6 +1677,7 @@ static void icl_display_core_uninit(struct
> drm_i915_private *dev_priv)
> return;
>
> gen9_disable_dc_states(dev_priv);
> + intel_dmc_disable_program(dev_priv);
>
> /* 1. Disable all display engine functions -> aready done */
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c
> b/drivers/gpu/drm/i915/display/intel_dmc.c
> index fa9ef591b8853..f73205d1f3164 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc.c
> +++ b/drivers/gpu/drm/i915/display/intel_dmc.c
> @@ -277,6 +277,17 @@ static void gen9_set_dc_state_debugmask(struct
> drm_i915_private *dev_priv)
> intel_de_posting_read(dev_priv, DC_STATE_DEBUG); }
>
> +static void disable_event_handler(struct drm_i915_private *i915,
> + i915_reg_t ctl_reg, i915_reg_t htp_reg) {
> + intel_de_write(i915, ctl_reg,
> + REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
> + DMC_EVT_CTL_TYPE_EDGE_0_1) |
> + REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
> + DMC_EVT_CTL_EVENT_ID_FALSE));
> + intel_de_write(i915, htp_reg, 0);
> +}
> +
> static void
> disable_flip_queue_event(struct drm_i915_private *i915,
> i915_reg_t ctl_reg, i915_reg_t htp_reg) @@ -299,12
> +310,7 @@ disable_flip_queue_event(struct drm_i915_private *i915,
> return;
> }
>
> - intel_de_write(i915, ctl_reg,
> - REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
> - DMC_EVT_CTL_TYPE_EDGE_0_1) |
> - REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
> - DMC_EVT_CTL_EVENT_ID_FALSE));
> - intel_de_write(i915, htp_reg, 0);
> + disable_event_handler(i915, ctl_reg, htp_reg);
> }
>
> static bool
> @@ -356,6 +362,27 @@ disable_all_flip_queue_events(struct drm_i915_private
> *i915)
> }
> }
>
> +static void disable_all_event_handlers(struct drm_i915_private *i915) {
> + int id;
> +
> + /* TODO: disable the event handlers on pre-GEN12 platforms as well */
> + if (DISPLAY_VER(i915) < 12)
> + return;
> +
> + for (id = DMC_FW_MAIN; id < DMC_FW_MAX; id++) {
> + int handler;
> +
> + if (!has_dmc_id_fw(i915, id))
> + continue;
> +
> + for (handler = 0; handler < DMC_EVENT_HANDLER_COUNT_GEN12;
> handler++)
> + disable_event_handler(i915,
> + DMC_EVT_CTL(i915, id, handler),
> + DMC_EVT_HTP(i915, id, handler));
> + }
> +}
> +
> /**
> * intel_dmc_load_program() - write the firmware from memory to register.
> * @dev_priv: i915 drm device.
> @@ -372,6 +399,8 @@ void intel_dmc_load_program(struct drm_i915_private
> *dev_priv)
> if (!intel_dmc_has_payload(dev_priv))
> return;
>
> + disable_all_event_handlers(dev_priv);
> +
> assert_rpm_wakelock_held(&dev_priv->runtime_pm);
>
> preempt_disable();
> @@ -405,6 +434,21 @@ void intel_dmc_load_program(struct drm_i915_private
> *dev_priv)
> disable_all_flip_queue_events(dev_priv);
> }
>
> +/**
> + * intel_dmc_disable_program() - disable the firmware
> + * @i915: i915 drm device
> + *
> + * Disable all event handlers in the firmware, making sure the firmware
> +is
> + * inactive after the display is uninitialized.
> + */
> +void intel_dmc_disable_program(struct drm_i915_private *i915) {
> + if (!intel_dmc_has_payload(i915))
> + return;
> +
> + disable_all_event_handlers(i915);
> +}
> +
> void assert_dmc_loaded(struct drm_i915_private *i915) {
> drm_WARN_ONCE(&i915->drm,
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc.h
> b/drivers/gpu/drm/i915/display/intel_dmc.h
> index 41091aee3b47b..67e03315ef999 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc.h
> +++ b/drivers/gpu/drm/i915/display/intel_dmc.h
> @@ -47,6 +47,7 @@ struct intel_dmc {
>
> void intel_dmc_ucode_init(struct drm_i915_private *i915); void
> intel_dmc_load_program(struct drm_i915_private *i915);
> +void intel_dmc_disable_program(struct drm_i915_private *i915);
> void intel_dmc_ucode_fini(struct drm_i915_private *i915); void
> intel_dmc_ucode_suspend(struct drm_i915_private *i915); void
> intel_dmc_ucode_resume(struct drm_i915_private *i915); diff --git
> a/drivers/gpu/drm/i915/display/intel_dmc_regs.h
> b/drivers/gpu/drm/i915/display/intel_dmc_regs.h
> index 238620b559662..5e5e41644ddfd 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc_regs.h
> +++ b/drivers/gpu/drm/i915/display/intel_dmc_regs.h
> @@ -28,6 +28,8 @@
> #define _DMC_REG(i915, dmc_id, reg) \
> ((reg) - __DMC_REG_MMIO_BASE + _DMC_REG_MMIO_BASE(i915, dmc_id))
>
> +#define DMC_EVENT_HANDLER_COUNT_GEN12 8
> +
> #define _DMC_EVT_HTP_0 0x8f004
>
> #define DMC_EVT_HTP(i915, dmc_id, handler) \
> --
> 2.34.1
