| Message ID | 20241028061418.3460461-1-arun.r.murthy@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [PATCHv3] drm/i915/dp: Guarantee a minimum HBlank time | expand |
> -----Original Message----- > From: Intel-xe <intel-xe-bounces@lists.freedesktop.org> On Behalf Of Arun R > Murthy > Sent: Monday, October 28, 2024 11:44 AM > To: intel-xe@lists.freedesktop.org; intel-gfx@lists.freedesktop.org > Cc: Nikula, Jani <jani.nikula@intel.com>; Murthy, Arun R > <arun.r.murthy@intel.com> > Subject: [PATCHv3] drm/i915/dp: Guarantee a minimum HBlank time > > Mandate a minimum Hblank symbol cycle count between BS and BE in 8b/10b > MST and 12b/132b mode. > Spec: DP2.1a > > v2: Affine calculation/updation of min HBlank to dp_mst (Jani) > v3: moved min_hblank from struct intel_dp to intel_crtc_state (Jani) > > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> > --- > drivers/gpu/drm/i915/display/intel_atomic.c | 1 + > drivers/gpu/drm/i915/display/intel_crtc.c | 1 + > .../drm/i915/display/intel_display_types.h | 1 + > drivers/gpu/drm/i915/display/intel_dp_mst.c | 28 +++++++++++++++++++ > drivers/gpu/drm/i915/i915_reg.h | 4 +++ > 5 files changed, 35 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c > b/drivers/gpu/drm/i915/display/intel_atomic.c > index 03dc54c802d3..24aa079efcad 100644 > --- a/drivers/gpu/drm/i915/display/intel_atomic.c > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c > @@ -278,6 +278,7 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc) > crtc_state->dsb_color_vblank = NULL; > crtc_state->dsb_commit = NULL; > crtc_state->use_dsb = false; > + crtc_state->min_hblank = 0; > > return &crtc_state->uapi; > } > diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c > b/drivers/gpu/drm/i915/display/intel_crtc.c > index 3c9168a57f38..472f3010bce4 100644 > --- a/drivers/gpu/drm/i915/display/intel_crtc.c > +++ b/drivers/gpu/drm/i915/display/intel_crtc.c > @@ -184,6 +184,7 @@ void intel_crtc_state_reset(struct intel_crtc_state > *crtc_state, > crtc_state->scaler_state.scaler_id = -1; > crtc_state->mst_master_transcoder = INVALID_TRANSCODER; > crtc_state->max_link_bpp_x16 = INT_MAX; > + crtc_state->min_hblank = 0; > } > > static struct intel_crtc *intel_crtc_alloc(void) diff --git > a/drivers/gpu/drm/i915/display/intel_display_types.h > b/drivers/gpu/drm/i915/display/intel_display_types.h > index 2bb1fa64da2f..7f631fef128e 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -1075,6 +1075,7 @@ struct intel_crtc_state { > > int max_link_bpp_x16; /* in 1/16 bpp units */ > int pipe_bpp; /* in 1 bpp units */ > + int min_hblank; /* min HBlank for DP2.1 */ > struct intel_link_m_n dp_m_n; > > /* m2_n2 for eDP downclock */ > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c > b/drivers/gpu/drm/i915/display/intel_dp_mst.c > index 1a2ff3e1cb68..2e088760a23a 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c > @@ -161,6 +161,28 @@ static int intel_dp_mst_dsc_get_slice_count(const > struct intel_connector *connec > num_joined_pipes); > } > > +static void intel_dp_mst_compute_min_hblank(struct intel_crtc_state > *crtc_state, > + struct intel_connector > *intel_connector, > + int bpp_x16) > +{ > + struct intel_encoder *intel_encoder = intel_connector->encoder; > + struct intel_display *intel_display = to_intel_display(intel_encoder); > + const struct drm_display_mode *adjusted_mode = > + &crtc_state->hw.adjusted_mode; > + u32 symbol_size = intel_dp_is_uhbr(crtc_state) ? 32 : 8; > + u32 hblank; > + > + if (DISPLAY_VER(intel_display) < 20) > + return; > + > + /* Calculate min Hblank Link Layer Symbol Cycle Count for 8b/10b MST > & 128b/132b */ > + hblank = DIV_ROUND_UP((DIV_ROUND_UP(adjusted_mode->htotal - > adjusted_mode->hdisplay, 4) * bpp_x16), symbol_size); > + if (intel_dp_is_uhbr(crtc_state)) > + crtc_state->min_hblank = (hblank > 5) ? hblank : 5; > + else > + crtc_state->min_hblank = (hblank > 3) ? hblank : 3; } > + > static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, > struct intel_crtc_state > *crtc_state, > int max_bpp, > @@ -238,6 +260,8 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct > intel_encoder *encoder, > remote_bw_overhead = intel_dp_mst_bw_overhead(crtc_state, > connector, > true, > dsc_slice_count, link_bpp_x16); > > + intel_dp_mst_compute_min_hblank(crtc_state, connector, > link_bpp_x16); > + > intel_dp_mst_compute_m_n(crtc_state, connector, > local_bw_overhead, > link_bpp_x16, > @@ -1292,6 +1316,10 @@ static void intel_mst_enable_dp(struct > intel_atomic_state *state, > TRANS_DP2_VFREQ_PIXEL_CLOCK(crtc_clock_hz & > 0xffffff)); > } > > + if (DISPLAY_VER(dev_priv) >= 20) > + intel_de_write(dev_priv, DP_MIN_HBLANK_CTL(dev_priv, > trans), > + pipe_config->min_hblank); > + intel_dp_mst_compute_min_hblank() calculates HBLANK_LL_SYM_CYC_CNT as per DP2.x specification which includes BS and BE framing control. Software driver needs to adjust these when programming minimum HBlank which doesn't include BS/BE framing control. Basically, we need to subtract 2 from pipe_config->min_hblank before programming. As per HW MMIO register, min_hblank can have a maximum value of 511, need to have these boundary conditions as well. > enable_bs_jitter_was(pipe_config); > > intel_ddi_enable_transcoder_func(encoder, pipe_config); diff --git > a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index > 405f409e9761..8aeed48f9170 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -1147,6 +1147,10 @@ > #define _TRANS_MULT_B 0x6102c > #define TRANS_MULT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), > _TRANS_MULT_A) > > +#define _DP_MIN_HBLANK_CTL_A 0x600ac > +#define _DP_MIN_HBLANK_CTL_B 0x610ac > +#define DP_MIN_HBLANK_CTL(dev_priv, trans) _MMIO_TRANS2(dev_priv, > (trans), _DP_MIN_HBLANK_CTL_A) > + > /* VGA port control */ > #define ADPA _MMIO(0x61100) > #define PCH_ADPA _MMIO(0xe1100) > -- > 2.25.1
On Mon, 28 Oct 2024, Arun R Murthy <arun.r.murthy@intel.com> wrote: > Mandate a minimum Hblank symbol cycle count between BS and BE in 8b/10b > MST and 12b/132b mode. > Spec: DP2.1a > > v2: Affine calculation/updation of min HBlank to dp_mst (Jani) > v3: moved min_hblank from struct intel_dp to intel_crtc_state (Jani) > > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> > --- > drivers/gpu/drm/i915/display/intel_atomic.c | 1 + > drivers/gpu/drm/i915/display/intel_crtc.c | 1 + > .../drm/i915/display/intel_display_types.h | 1 + > drivers/gpu/drm/i915/display/intel_dp_mst.c | 28 +++++++++++++++++++ > drivers/gpu/drm/i915/i915_reg.h | 4 +++ > 5 files changed, 35 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c > index 03dc54c802d3..24aa079efcad 100644 > --- a/drivers/gpu/drm/i915/display/intel_atomic.c > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c > @@ -278,6 +278,7 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc) > crtc_state->dsb_color_vblank = NULL; > crtc_state->dsb_commit = NULL; > crtc_state->use_dsb = false; > + crtc_state->min_hblank = 0; > > return &crtc_state->uapi; > } > diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c > index 3c9168a57f38..472f3010bce4 100644 > --- a/drivers/gpu/drm/i915/display/intel_crtc.c > +++ b/drivers/gpu/drm/i915/display/intel_crtc.c > @@ -184,6 +184,7 @@ void intel_crtc_state_reset(struct intel_crtc_state *crtc_state, > crtc_state->scaler_state.scaler_id = -1; > crtc_state->mst_master_transcoder = INVALID_TRANSCODER; > crtc_state->max_link_bpp_x16 = INT_MAX; > + crtc_state->min_hblank = 0; > } > > static struct intel_crtc *intel_crtc_alloc(void) > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index 2bb1fa64da2f..7f631fef128e 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -1075,6 +1075,7 @@ struct intel_crtc_state { > > int max_link_bpp_x16; /* in 1/16 bpp units */ > int pipe_bpp; /* in 1 bpp units */ > + int min_hblank; /* min HBlank for DP2.1 */ > struct intel_link_m_n dp_m_n; > > /* m2_n2 for eDP downclock */ > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c > index 1a2ff3e1cb68..2e088760a23a 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c > @@ -161,6 +161,28 @@ static int intel_dp_mst_dsc_get_slice_count(const struct intel_connector *connec > num_joined_pipes); > } > > +static void intel_dp_mst_compute_min_hblank(struct intel_crtc_state *crtc_state, > + struct intel_connector *intel_connector, Always name struct intel_connector *connector, not intel_connector. That's what the style has been for years now, though not everything's been converted. > + int bpp_x16) > +{ > + struct intel_encoder *intel_encoder = intel_connector->encoder; Ditto, just encoder. > + struct intel_display *intel_display = to_intel_display(intel_encoder); Just display. Always. Everywhere. Make this the first local variable whenever possible. > + const struct drm_display_mode *adjusted_mode = > + &crtc_state->hw.adjusted_mode; > + u32 symbol_size = intel_dp_is_uhbr(crtc_state) ? 32 : 8; > + u32 hblank; Looks like these should be ints. > + > + if (DISPLAY_VER(intel_display) < 20) > + return; > + > + /* Calculate min Hblank Link Layer Symbol Cycle Count for 8b/10b MST & 128b/132b */ > + hblank = DIV_ROUND_UP((DIV_ROUND_UP(adjusted_mode->htotal - adjusted_mode->hdisplay, 4) * bpp_x16), symbol_size); Okay so I didn't really think this through, but 1) do we lose precision by dividing by 4 first, and multiplying by bpp_x16 next, and 2) how does this take into account that bpp_x16 is in fact the x16 value? > + if (intel_dp_is_uhbr(crtc_state)) > + crtc_state->min_hblank = (hblank > 5) ? hblank : 5; > + else > + crtc_state->min_hblank = (hblank > 3) ? hblank : 3; These look like hand-rolled max() that needlessly duplicate both hblank and the constant. > +} > + > static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, > struct intel_crtc_state *crtc_state, > int max_bpp, > @@ -238,6 +260,8 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, > remote_bw_overhead = intel_dp_mst_bw_overhead(crtc_state, connector, > true, dsc_slice_count, link_bpp_x16); > > + intel_dp_mst_compute_min_hblank(crtc_state, connector, link_bpp_x16); > + > intel_dp_mst_compute_m_n(crtc_state, connector, > local_bw_overhead, > link_bpp_x16, > @@ -1292,6 +1316,10 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state, > TRANS_DP2_VFREQ_PIXEL_CLOCK(crtc_clock_hz & 0xffffff)); > } > > + if (DISPLAY_VER(dev_priv) >= 20) Always use the display local var when possible. DISPLAY_VER(display) > + intel_de_write(dev_priv, DP_MIN_HBLANK_CTL(dev_priv, trans), > + pipe_config->min_hblank); intel_de_write(display, .... DP_MIN_HBLANK_CTL(display, trans) ... > + > enable_bs_jitter_was(pipe_config); > > intel_ddi_enable_transcoder_func(encoder, pipe_config); > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h > index 405f409e9761..8aeed48f9170 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -1147,6 +1147,10 @@ > #define _TRANS_MULT_B 0x6102c > #define TRANS_MULT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _TRANS_MULT_A) > > +#define _DP_MIN_HBLANK_CTL_A 0x600ac > +#define _DP_MIN_HBLANK_CTL_B 0x610ac > +#define DP_MIN_HBLANK_CTL(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _DP_MIN_HBLANK_CTL_A) > + > /* VGA port control */ > #define ADPA _MMIO(0x61100) > #define PCH_ADPA _MMIO(0xe1100)
On Mon, Oct 28, 2024 at 11:44:18AM +0530, Arun R Murthy wrote: > Mandate a minimum Hblank symbol cycle count between BS and BE in 8b/10b > MST and 12b/132b mode. > Spec: DP2.1a > > v2: Affine calculation/updation of min HBlank to dp_mst (Jani) > v3: moved min_hblank from struct intel_dp to intel_crtc_state (Jani) > > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> > --- > drivers/gpu/drm/i915/display/intel_atomic.c | 1 + > drivers/gpu/drm/i915/display/intel_crtc.c | 1 + > .../drm/i915/display/intel_display_types.h | 1 + > drivers/gpu/drm/i915/display/intel_dp_mst.c | 28 +++++++++++++++++++ > drivers/gpu/drm/i915/i915_reg.h | 4 +++ Missing state dump and checker. > 5 files changed, 35 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c > index 03dc54c802d3..24aa079efcad 100644 > --- a/drivers/gpu/drm/i915/display/intel_atomic.c > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c > @@ -278,6 +278,7 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc) > crtc_state->dsb_color_vblank = NULL; > crtc_state->dsb_commit = NULL; > crtc_state->use_dsb = false; > + crtc_state->min_hblank = 0; This doesn't look like something that should be reset here. > > return &crtc_state->uapi; > } > diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c > index 3c9168a57f38..472f3010bce4 100644 > --- a/drivers/gpu/drm/i915/display/intel_crtc.c > +++ b/drivers/gpu/drm/i915/display/intel_crtc.c > @@ -184,6 +184,7 @@ void intel_crtc_state_reset(struct intel_crtc_state *crtc_state, > crtc_state->scaler_state.scaler_id = -1; > crtc_state->mst_master_transcoder = INVALID_TRANSCODER; > crtc_state->max_link_bpp_x16 = INT_MAX; > + crtc_state->min_hblank = 0; Pointless. > } > > static struct intel_crtc *intel_crtc_alloc(void) > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index 2bb1fa64da2f..7f631fef128e 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -1075,6 +1075,7 @@ struct intel_crtc_state { > > int max_link_bpp_x16; /* in 1/16 bpp units */ > int pipe_bpp; /* in 1 bpp units */ > + int min_hblank; /* min HBlank for DP2.1 */ > struct intel_link_m_n dp_m_n; > > /* m2_n2 for eDP downclock */ > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c > index 1a2ff3e1cb68..2e088760a23a 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c > @@ -161,6 +161,28 @@ static int intel_dp_mst_dsc_get_slice_count(const struct intel_connector *connec > num_joined_pipes); > } > > +static void intel_dp_mst_compute_min_hblank(struct intel_crtc_state *crtc_state, > + struct intel_connector *intel_connector, > + int bpp_x16) > +{ > + struct intel_encoder *intel_encoder = intel_connector->encoder; > + struct intel_display *intel_display = to_intel_display(intel_encoder); > + const struct drm_display_mode *adjusted_mode = > + &crtc_state->hw.adjusted_mode; > + u32 symbol_size = intel_dp_is_uhbr(crtc_state) ? 32 : 8; > + u32 hblank; > + > + if (DISPLAY_VER(intel_display) < 20) > + return; > + > + /* Calculate min Hblank Link Layer Symbol Cycle Count for 8b/10b MST & 128b/132b */ > + hblank = DIV_ROUND_UP((DIV_ROUND_UP(adjusted_mode->htotal - adjusted_mode->hdisplay, 4) * bpp_x16), symbol_size); > + if (intel_dp_is_uhbr(crtc_state)) > + crtc_state->min_hblank = (hblank > 5) ? hblank : 5; > + else > + crtc_state->min_hblank = (hblank > 3) ? hblank : 3; > +} This looks like it should/could be a pure function. > + > static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, > struct intel_crtc_state *crtc_state, > int max_bpp, > @@ -238,6 +260,8 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, > remote_bw_overhead = intel_dp_mst_bw_overhead(crtc_state, connector, > true, dsc_slice_count, link_bpp_x16); > > + intel_dp_mst_compute_min_hblank(crtc_state, connector, link_bpp_x16); > + > intel_dp_mst_compute_m_n(crtc_state, connector, > local_bw_overhead, > link_bpp_x16, > @@ -1292,6 +1316,10 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state, > TRANS_DP2_VFREQ_PIXEL_CLOCK(crtc_clock_hz & 0xffffff)); > } > > + if (DISPLAY_VER(dev_priv) >= 20) > + intel_de_write(dev_priv, DP_MIN_HBLANK_CTL(dev_priv, trans), > + pipe_config->min_hblank); > + > enable_bs_jitter_was(pipe_config); > > intel_ddi_enable_transcoder_func(encoder, pipe_config); > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h > index 405f409e9761..8aeed48f9170 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -1147,6 +1147,10 @@ > #define _TRANS_MULT_B 0x6102c > #define TRANS_MULT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _TRANS_MULT_A) > > +#define _DP_MIN_HBLANK_CTL_A 0x600ac > +#define _DP_MIN_HBLANK_CTL_B 0x610ac > +#define DP_MIN_HBLANK_CTL(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _DP_MIN_HBLANK_CTL_A) Please insert this into the proper spot based on the register offset. _MMIO_TRANS2 is pointless overhead for platform as new as this. > + > /* VGA port control */ > #define ADPA _MMIO(0x61100) > #define PCH_ADPA _MMIO(0xe1100) > -- > 2.25.1
> > + > > + if (DISPLAY_VER(intel_display) < 20) > > + return; > > + > > + /* Calculate min Hblank Link Layer Symbol Cycle Count for 8b/10b MST > & 128b/132b */ > > + hblank = DIV_ROUND_UP((DIV_ROUND_UP(adjusted_mode->htotal - > > +adjusted_mode->hdisplay, 4) * bpp_x16), symbol_size); > > Okay so I didn't really think this through, but 1) do we lose precision by dividing > by 4 first, and multiplying by bpp_x16 next, and 2) how does this take into > account that bpp_x16 is in fact the x16 value? > Spec doesn't highlight more on precision, so should be fine losing the precision. x16 is obtained from fxp_q4_form_int Thanks and Regards, Arun R Murthy -------------------
diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c index 03dc54c802d3..24aa079efcad 100644 --- a/drivers/gpu/drm/i915/display/intel_atomic.c +++ b/drivers/gpu/drm/i915/display/intel_atomic.c @@ -278,6 +278,7 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc) crtc_state->dsb_color_vblank = NULL; crtc_state->dsb_commit = NULL; crtc_state->use_dsb = false; + crtc_state->min_hblank = 0; return &crtc_state->uapi; } diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c index 3c9168a57f38..472f3010bce4 100644 --- a/drivers/gpu/drm/i915/display/intel_crtc.c +++ b/drivers/gpu/drm/i915/display/intel_crtc.c @@ -184,6 +184,7 @@ void intel_crtc_state_reset(struct intel_crtc_state *crtc_state, crtc_state->scaler_state.scaler_id = -1; crtc_state->mst_master_transcoder = INVALID_TRANSCODER; crtc_state->max_link_bpp_x16 = INT_MAX; + crtc_state->min_hblank = 0; } static struct intel_crtc *intel_crtc_alloc(void) diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 2bb1fa64da2f..7f631fef128e 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -1075,6 +1075,7 @@ struct intel_crtc_state { int max_link_bpp_x16; /* in 1/16 bpp units */ int pipe_bpp; /* in 1 bpp units */ + int min_hblank; /* min HBlank for DP2.1 */ struct intel_link_m_n dp_m_n; /* m2_n2 for eDP downclock */ diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 1a2ff3e1cb68..2e088760a23a 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -161,6 +161,28 @@ static int intel_dp_mst_dsc_get_slice_count(const struct intel_connector *connec num_joined_pipes); } +static void intel_dp_mst_compute_min_hblank(struct intel_crtc_state *crtc_state, + struct intel_connector *intel_connector, + int bpp_x16) +{ + struct intel_encoder *intel_encoder = intel_connector->encoder; + struct intel_display *intel_display = to_intel_display(intel_encoder); + const struct drm_display_mode *adjusted_mode = + &crtc_state->hw.adjusted_mode; + u32 symbol_size = intel_dp_is_uhbr(crtc_state) ? 32 : 8; + u32 hblank; + + if (DISPLAY_VER(intel_display) < 20) + return; + + /* Calculate min Hblank Link Layer Symbol Cycle Count for 8b/10b MST & 128b/132b */ + hblank = DIV_ROUND_UP((DIV_ROUND_UP(adjusted_mode->htotal - adjusted_mode->hdisplay, 4) * bpp_x16), symbol_size); + if (intel_dp_is_uhbr(crtc_state)) + crtc_state->min_hblank = (hblank > 5) ? hblank : 5; + else + crtc_state->min_hblank = (hblank > 3) ? hblank : 3; +} + static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, struct intel_crtc_state *crtc_state, int max_bpp, @@ -238,6 +260,8 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, remote_bw_overhead = intel_dp_mst_bw_overhead(crtc_state, connector, true, dsc_slice_count, link_bpp_x16); + intel_dp_mst_compute_min_hblank(crtc_state, connector, link_bpp_x16); + intel_dp_mst_compute_m_n(crtc_state, connector, local_bw_overhead, link_bpp_x16, @@ -1292,6 +1316,10 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state, TRANS_DP2_VFREQ_PIXEL_CLOCK(crtc_clock_hz & 0xffffff)); } + if (DISPLAY_VER(dev_priv) >= 20) + intel_de_write(dev_priv, DP_MIN_HBLANK_CTL(dev_priv, trans), + pipe_config->min_hblank); + enable_bs_jitter_was(pipe_config); intel_ddi_enable_transcoder_func(encoder, pipe_config); diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 405f409e9761..8aeed48f9170 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -1147,6 +1147,10 @@ #define _TRANS_MULT_B 0x6102c #define TRANS_MULT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _TRANS_MULT_A) +#define _DP_MIN_HBLANK_CTL_A 0x600ac +#define _DP_MIN_HBLANK_CTL_B 0x610ac +#define DP_MIN_HBLANK_CTL(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _DP_MIN_HBLANK_CTL_A) + /* VGA port control */ #define ADPA _MMIO(0x61100) #define PCH_ADPA _MMIO(0xe1100)
Mandate a minimum Hblank symbol cycle count between BS and BE in 8b/10b MST and 12b/132b mode. Spec: DP2.1a v2: Affine calculation/updation of min HBlank to dp_mst (Jani) v3: moved min_hblank from struct intel_dp to intel_crtc_state (Jani) Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> --- drivers/gpu/drm/i915/display/intel_atomic.c | 1 + drivers/gpu/drm/i915/display/intel_crtc.c | 1 + .../drm/i915/display/intel_display_types.h | 1 + drivers/gpu/drm/i915/display/intel_dp_mst.c | 28 +++++++++++++++++++ drivers/gpu/drm/i915/i915_reg.h | 4 +++ 5 files changed, 35 insertions(+)