On Sat, Oct 13, 2018 at 12:02:25AM +0530, Sharma, Shashank wrote:
> Regards
>
> Shashank
>
>
> On 10/12/2018 11:39 PM, Ville Syrjälä wrote:
> > On Fri, Oct 12, 2018 at 11:21:56PM +0530, Sharma, Shashank wrote:
> >> Regards
> >>
> >> Shashank
> >>
> >>
> >> On 10/12/2018 7:28 PM, Ville Syrjälä wrote:
> >>> On Fri, Oct 12, 2018 at 11:53:14AM +0530, Shashank Sharma wrote:
> >>>> From: Shashank Sharma <shashank.sharma@xxxxxxxxxxxxxxx>
> >>>>
> >>>> LSPCON chips can generate YCBCR outputs, if asked nicely :).
> >>>>
> >>>> In order to generate YCBCR 4:2:0 outputs, a source must:
> >>>> - send YCBCR 4:4:4 signals to LSPCON
> >>>> - program color space as 4:2:0 in AVI infoframes
> >>>>
> >>>> Whereas for YCBCR 4:4:4 outputs, the source must:
> >>>> - send YCBCR 4:4:4 signals to LSPCON
> >>>> - program color space as 4:4:4 in AVI infoframes
> >>>>
> >>>> So for both 4:2:0 as well as 4:4:4 outputs, we are driving the
> >>>> pipe for YCBCR 4:4:4 output, but AVI infoframe's color space
> >>>> information indicates LSPCON FW to start scaling down from YCBCR
> >>>> 4:4:4 and generate YCBCR 4:2:0 output. As the scaling is done by
> >>>> LSPCON device, we need not to reserve a scaler for 4:2:0 outputs.
> >>>>
> >>>> V2: rebase
> >>>> V3: Addressed review comments from Ville
> >>>> - add enum crtc_output_format instead of bool ycbcr420
> >>>> - use crtc_output_format=4:4:4 for modeset of LSPCON 4:2:0 output
> >>>> cases in this way we will have YCBCR 4:4:4 framework ready (except
> >>>> the ABI part)
> >>>> V4: Added r-b from Maarten (for v3)
> >>>> Addressed review comments from Ville:
> >>>> - Do not add a non-atomic state variable to determine lspcon output.
> >>>> Instead add bool in CRTC state to indicate lspcon based scaling.
> >>>> V5: Addressed review comments from Ville:
> >>>> - Change the state bool name from external scaling to something more
> >>>> relavent.
> >>>> - Keep the info and adjusted_mode structures const.
> >>>> - use crtc_state instead of pipe_config.
> >>>> - Push all the config change into lspcon_ycbcr420_config function.
> >>>> V6: Rebase, small changes to accommodate changes in patch 2.
> >>>> V7: Fixed checkpatch warnings for alignment
> >>>> V8: Rebase
> >>>>
> >>>> PS: Ignored following warnings to match the current formatting:
> >>>> drm/i915: Add YCBCR 4:2:0/4:4:4 support for LSPCON
> >>>> -:53: CHECK:SPACING: spaces preferred around that '<<' (ctx:VxV)
> >>>> #53: FILE: drivers/gpu/drm/i915/i915_reg.h:8721:
> >>>> +#define TRANS_MSA_SAMPLING_444 (2<<1)
> >>>> ^
> >>>> -:54: CHECK:SPACING: spaces preferred around that '<<' (ctx:VxV)
> >>>> #54: FILE: drivers/gpu/drm/i915/i915_reg.h:8722:
> >>>> +#define TRANS_MSA_CLRSP_YCBCR (2<<3)
> >>>> V9: Rebase
> >>>> V10: Rebase
> >>>> V11: Rebase
> >>>>
> >>>> Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
> >>>> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> >>>> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> >>>> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
> >>>> ---
> >>>> drivers/gpu/drm/i915/i915_reg.h | 2 ++
> >>>> drivers/gpu/drm/i915/intel_ddi.c | 7 +++++++
> >>>> drivers/gpu/drm/i915/intel_display.c | 12 ++++++++++++
> >>>> drivers/gpu/drm/i915/intel_dp.c | 4 ++++
> >>>> drivers/gpu/drm/i915/intel_drv.h | 5 +++++
> >>>> drivers/gpu/drm/i915/intel_lspcon.c | 26 ++++++++++++++++++++++++++
> >>>> 6 files changed, 56 insertions(+)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> >>>> index 2078541..1e13e51 100644
> >>>> --- a/drivers/gpu/drm/i915/i915_reg.h
> >>>> +++ b/drivers/gpu/drm/i915/i915_reg.h
> >>>> @@ -9229,6 +9229,8 @@ enum skl_power_gate {
> >>>> #define TRANS_MSA_MISC(tran) _MMIO_TRANS2(tran, _TRANSA_MSA_MISC)
> >>>>
> >>>> #define TRANS_MSA_SYNC_CLK (1 << 0)
> >>>> +#define TRANS_MSA_SAMPLING_444 (2 << 1)
> >>>> +#define TRANS_MSA_CLRSP_YCBCR (2 << 3)
> >>>> #define TRANS_MSA_6_BPC (0 << 5)
> >>>> #define TRANS_MSA_8_BPC (1 << 5)
> >>>> #define TRANS_MSA_10_BPC (2 << 5)
> >>>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> >>>> index be21131..186111a 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_ddi.c
> >>>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> >>>> @@ -1784,6 +1784,13 @@ void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
> >>>> break;
> >>>> }
> >>>>
> >>>> + /*
> >>>> + * As per DP 1.2 spec section 2.3.4.3 while sending
> >>>> + * YCBCR 444 signals we should program MSA MISC1/0 fields with
> >>>> + * colorspace information. The output colorspace encoding is BT601.
> >>>> + */
> >>>> + if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444)
> >>>> + temp |= TRANS_MSA_SAMPLING_444 | TRANS_MSA_CLRSP_YCBCR;
> >>>> I915_WRITE(TRANS_MSA_MISC(cpu_transcoder), temp);
> >>>> }
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >>>> index 3317c6c..41abd03 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_display.c
> >>>> +++ b/drivers/gpu/drm/i915/intel_display.c
> >>>> @@ -7797,6 +7797,8 @@ static void intel_get_crtc_ycbcr_config(struct intel_crtc *crtc,
> >>>> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> >>>> enum intel_output_format output = INTEL_OUTPUT_FORMAT_RGB;
> >>>>
> >>>> + pipe_config->lspcon_downsampling = false;
> >>>> +
> >>>> if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9) {
> >>>> u32 tmp = I915_READ(PIPEMISC(crtc->pipe));
> >>>>
> >>>> @@ -7814,6 +7816,16 @@ static void intel_get_crtc_ycbcr_config(struct intel_crtc *crtc,
> >>>> else
> >>>> output = INTEL_OUTPUT_FORMAT_YCBCR420;
> >>>> } else {
> >>>> + /*
> >>>> + * Currently there is no interface defined to
> >>>> + * check user preference between RGB/YCBCR444
> >>>> + * or YCBCR420. So the only possible case for
> >>>> + * YCBCR444 usage is driving YCBCR420 output
> >>>> + * with LSPCON, when pipe is configured for
> >>>> + * YCBCR444 output and LSPCON takes care of
> >>>> + * downsampling it.
> >>>> + */
> >>>> + pipe_config->lspcon_downsampling = true;
> >>>> output = INTEL_OUTPUT_FORMAT_YCBCR444;
> >>>> }
> >>>> }
> >>>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> >>>> index c3f6330..1156d59 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_dp.c
> >>>> +++ b/drivers/gpu/drm/i915/intel_dp.c
> >>>> @@ -2074,6 +2074,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
> >>>> struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> >>>> struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> >>>> struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> >>>> + struct intel_lspcon *lspcon = enc_to_intel_lspcon(&encoder->base);
> >>>> enum port port = encoder->port;
> >>>> struct intel_crtc *intel_crtc = to_intel_crtc(pipe_config->base.crtc);
> >>>> struct intel_connector *intel_connector = intel_dp->attached_connector;
> >>>> @@ -2086,6 +2087,9 @@ intel_dp_compute_config(struct intel_encoder *encoder,
> >>>> pipe_config->has_pch_encoder = true;
> >>>>
> >>>> pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
> >>>> + if (lspcon->active)
> >>>> + lspcon_ycbcr420_config(&intel_connector->base, pipe_config);
> >>>> +
> >>>> pipe_config->has_drrs = false;
> >>>> if (IS_G4X(dev_priv) || port == PORT_A)
> >>>> pipe_config->has_audio = false;
> >>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >>>> index b8e5f95..95e252e 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_drv.h
> >>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >>>> @@ -908,6 +908,9 @@ struct intel_crtc_state {
> >>>>
> >>>> /* Output format RGB/YCBCR etc */
> >>>> enum intel_output_format output_format;
> >>>> +
> >>>> + /* Output down scaling is done in LSPCON device */
> >>>> + bool lspcon_downsampling;
> >>>> };
> >>>>
> >>>> struct intel_crtc {
> >>>> @@ -2225,6 +2228,8 @@ void lspcon_set_infoframes(struct intel_encoder *encoder,
> >>>> const struct drm_connector_state *conn_state);
> >>>> bool lspcon_infoframe_enabled(struct intel_encoder *encoder,
> >>>> const struct intel_crtc_state *pipe_config);
> >>>> +void lspcon_ycbcr420_config(struct drm_connector *connector,
> >>>> + struct intel_crtc_state *crtc_state);
> >>>>
> >>>> /* intel_pipe_crc.c */
> >>>> #ifdef CONFIG_DEBUG_FS
> >>>> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
> >>>> index 829c40a..fff32b3 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_lspcon.c
> >>>> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
> >>>> @@ -180,6 +180,21 @@ static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
> >>>> return true;
> >>>> }
> >>>>
> >>>> +void lspcon_ycbcr420_config(struct drm_connector *connector,
> >>>> + struct intel_crtc_state *crtc_state)
> >>>> +{
> >>>> + const struct drm_display_info *info = &connector->display_info;
> >>>> + const struct drm_display_mode *adjusted_mode =
> >>>> + &crtc_state->base.adjusted_mode;
> >>>> +
> >>>> + if (drm_mode_is_420_only(info, adjusted_mode) &&
> >>>> + connector->ycbcr_420_allowed) {
> >>>> + crtc_state->port_clock /= 2;
> >>> This looks bogus. We're talking about DP here so we should not be
> >>> frobbing port_clock. And since we output 4:4:4 from the port
> >>> anyway we don't even have to take 4:2:0 into consideration
> >>> when calculating port_clock.
> >> I agree on this.
> >>> Ah, this guy is called before we even calculate port_clock.
> >>> That explains why this didn't cause any problems. So this is
> >>> just dead code here.
> >>>
> >>> And looks like the port_clock adjustment in intel_hdmi_ycbcr420_config()
> >>> also dead code since the caller overwrites it there as well.
> >> I am not sure if that's the case for Native HDMI 2.0.
> >> In intel_hdmi_420_config we are updating the config->port_clock, which
> >> is the same thing being updated for 8/12/16 BPC deep color too, just
> >> after this function.
> >> I have tested the output with HDMI 2.0 analyzer, which reported right
> >> pixel clock (297Mhz). Now, as any of the port clock calculations do not
> >> get information
> >> about HDMI output type, there is no other way they will calculate the
> >> right pixel clock (594/2) for 4:2:0 outputs. So I believe that code is
> >> active.
> > It effectively does this:
> >
> > 1. port_clock = who knows
> > 2. port_clock /= 2;
> Here, in intel_hdmi_compute_ycbcr_config() function, we are additionally
> doing this also:
>
> clock_8bpc /= 2;
> clock_10bpc /= 2;
> clock_12bpc /= 2;
>
> > 3. if (12bpc)
> > port_clock = clock_12bpc;
> > else if (10bpc)
> > port_clock = clock_10bpc;
> > else
> > port_clock = clock_8bpc;
> This means effectively the selected clock is /2, so the code is not dead
> (thankfully :-))
Only the port_clock/=2 part. I never claimed the rest was dead.
> - Shashank
> >
> > Ie. step 2. is dead code.
> >
> >> - Shashank
> >>>> + crtc_state->output_format = INTEL_OUTPUT_FORMAT_YCBCR444;
> >>>> + crtc_state->lspcon_downsampling = true;
> >>>> + }
> >>>> +}
> >>>> +
> >>>> static bool lspcon_probe(struct intel_lspcon *lspcon)
> >>>> {
> >>>> int retry;
> >>>> @@ -464,6 +479,15 @@ void lspcon_set_infoframes(struct intel_encoder *encoder,
> >>>> return;
> >>>> }
> >>>>
> >>>> + if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444) {
> >>>> + if (crtc_state->lspcon_downsampling)
> >>>> + frame.avi.colorspace = HDMI_COLORSPACE_YUV420;
> >>>> + else
> >>>> + frame.avi.colorspace = HDMI_COLORSPACE_YUV444;
> >>>> + } else {
> >>>> + frame.avi.colorspace = HDMI_COLORSPACE_RGB;
> >>>> + }
> >>>> +
> >>>> drm_hdmi_avi_infoframe_quant_range(&frame.avi, mode,
> >>>> crtc_state->limited_color_range ?
> >>>> HDMI_QUANTIZATION_RANGE_LIMITED :
> >>>> @@ -517,6 +541,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
> >>>> struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
> >>>> struct drm_device *dev = intel_dig_port->base.base.dev;
> >>>> struct drm_i915_private *dev_priv = to_i915(dev);
> >>>> + struct drm_connector *connector = &dp->attached_connector->base;
> >>>>
> >>>> if (!HAS_LSPCON(dev_priv)) {
> >>>> DRM_ERROR("LSPCON is not supported on this platform\n");
> >>>> @@ -541,6 +566,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
> >>>> return false;
> >>>> }
> >>>>
> >>>> + connector->ycbcr_420_allowed = true;
> >>>> lspcon->active = true;
> >>>> DRM_DEBUG_KMS("Success: LSPCON init\n");
> >>>> return true;
> >>>> --
> >>>> 2.7.4
--
Ville Syrjälä
Intel
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