[RESEND-CI v4 11/15] drm/i915: prepare scaler for YCBCR420 modeset
Sharma, Shashank
shashank.sharma at intel.com
Fri Jun 30 11:59:08 UTC 2017
Regards
Shashank
On 6/30/2017 5:04 PM, Ander Conselvan De Oliveira wrote:
> On Fri, 2017-06-30 at 11:20 +0530, Sharma, Shashank wrote:
>> Regards
>>
>> Shashank
>>
>>
>> On 6/27/2017 5:46 PM, Ander Conselvan De Oliveira wrote:
>>> On Wed, 2017-06-21 at 16:04 +0530, Shashank Sharma wrote:
>>>> To get a YCBCR420 output from intel platforms, we need one
>>>> scaler to scale down YCBCR444 samples to YCBCR420 samples.
>>>>
>>>> This patch:
>>>> - Does scaler allocation for HDMI ycbcr420 outputs.
>>>> - Programs PIPE_MISC register for ycbcr420 output.
>>>> - Adds a new scaler user "HDMI output" to plug-into existing
>>>> scaler framework. This output type is identified using bit
>>>> 30 of the scaler users bitmap.
>>>>
>>>> V2: rebase
>>>> V3: rebase
>>>> V4: rebase
>>>>
>>>> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
>>>> Cc: Ander Conselvan De Oliveira <ander.conselvan.de.oliveira at intel.com>
>>>> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
>>>> ---
>>>> drivers/gpu/drm/i915/intel_atomic.c | 6 ++++++
>>>> drivers/gpu/drm/i915/intel_display.c | 26 ++++++++++++++++++++++++++
>>>> drivers/gpu/drm/i915/intel_drv.h | 10 +++++++++-
>>>> drivers/gpu/drm/i915/intel_hdmi.c | 10 ++++++++++
>>>> drivers/gpu/drm/i915/intel_panel.c | 3 ++-
>>>> 5 files changed, 53 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/intel_atomic.c b/drivers/gpu/drm/i915/intel_atomic.c
>>>> index 36d4e63..a8c9ac5 100644
>>>> --- a/drivers/gpu/drm/i915/intel_atomic.c
>>>> +++ b/drivers/gpu/drm/i915/intel_atomic.c
>>>> @@ -264,6 +264,12 @@ int intel_atomic_setup_scalers(struct drm_i915_private *dev_priv,
>>>>
>>>> /* panel fitter case: assign as a crtc scaler */
>>>> scaler_id = &scaler_state->scaler_id;
>>>> + } else if (i == SKL_HDMI_OUTPUT_INDEX) {
>>>> + name = "HDMI-OUTPUT";
>>>> + idx = intel_crtc->base.base.id;
>>>> +
>>>> + /* hdmi output case: needs a pipe scaler */
>>>> + scaler_id = &scaler_state->scaler_id;
>>>> } else {
>>>> name = "PLANE";
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>>>> index da29536..983f581 100644
>>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>>> @@ -4626,6 +4626,11 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>>>> */
>>>> need_scaling = src_w != dst_w || src_h != dst_h;
>>>>
>>>> + if (crtc_state->hdmi_output == DRM_HDMI_OUTPUT_YCBCR420
>>>> + && scaler_user == SKL_HDMI_OUTPUT_INDEX)
>>> Is it really necessary to check for both? If it is, what's the point of creating
>>> SKL_HDMI_OUTPUT_INDEX?
>> Yes, else this will affect scaler update for planes, as this function
>> gets called to update the plane scalers too, at that time the output
>> will be still valid (as its at CRTC level), but the
>> scaler user would be different.
> Right, so there is a need to check for scaler_user == HDMI_OUTPUT. But then
> wouldn't it be a bug if hdmi_output != YCBCR420 ? Point is, if the caller asked
> for a HDMI_OUTPUT scaler hopefully it knows what its doing, no need to second
> guess it.
skl_update_scaler function gets called for all the users, which are:
- panel fitter
- all the planes
- newly added user hdmi_output
what about the case (assume) when we have handled hdmi_output and now we
are handling for a plane, which doesnt need scaling.
in this case, the code will look like:
if (crtc_state->hdmi_output == DRM_HDMI_OUTPUT_YCBCR420)
need_scaling = true /* which is wrong, as this function call is
for plane scalar, and scaler_user = scaler */
if (crtc_state->hdmi_output == DRM_HDMI_OUTPUT_YCBCR420 &&
scaler_user == HDMI_OUT)
need_scaling = true /* this is correct, as I want to consume scalar only when both the conditions are true.
>>>> + /* YCBCR 444 -> 420 conversion needs a scaler */
>>>> + need_scaling = true;
>>>> +
>>>> /*
>>>> * if plane is being disabled or scaler is no more required or force detach
>>>> * - free scaler binded to this plane/crtc
>>>> @@ -4673,6 +4678,26 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>>>> }
>>>>
>>>> /**
>>>> + * skl_update_scaler_hdmi_output - Stages update to scaler state for HDMI.
>>>> + * HDMI YCBCR 420 output needs a scaler, for downsampling.
>>>> + *
>>>> + * @state: crtc's scaler state
>>>> + *
>>>> + * Return
>>>> + * 0 - scaler_usage updated successfully
>>>> + * error - requested scaling cannot be supported or other error condition
>>>> + */
>>>> +int skl_update_scaler_crtc_hdmi_output(struct intel_crtc_state *state)
>>>> +{
>>>> + const struct drm_display_mode *mode = &state->base.adjusted_mode;
>>>> +
>>>> + return skl_update_scaler(state, !state->base.active,
>>>> + SKL_HDMI_OUTPUT_INDEX, &state->scaler_state.scaler_id,
>>>> + state->pipe_src_w, state->pipe_src_h,
>>>> + mode->crtc_hdisplay, mode->crtc_vdisplay);
>>>> +}
>>>> +
>>>> +/**
>>>> * skl_update_scaler_crtc - Stages update to scaler state for a given crtc.
>>>> *
>>>> * @state: crtc's scaler state
>>>> @@ -8058,6 +8083,7 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
>>>> {
>>>> struct drm_i915_private *dev_priv = to_i915(crtc->dev);
>>>> struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
>>>> + enum drm_hdmi_output_type hdmi_out = intel_crtc->config->hdmi_output;
>>>>
>>>> if (IS_BROADWELL(dev_priv) || INTEL_INFO(dev_priv)->gen >= 9) {
>>>> u32 val = 0;
>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>> index 38fe56c..2206aa8 100644
>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>> @@ -471,7 +471,8 @@ struct intel_crtc_scaler_state {
>>>> *
>>>> * If a bit is set, a user is using a scaler.
>>>> * Here user can be a plane or crtc as defined below:
>>>> - * bits 0-30 - plane (bit position is index from drm_plane_index)
>>>> + * bits 0-29 - plane (bit position is index from drm_plane_index)
>>>> + * bit 30 - hdmi output
>>>> * bit 31 - crtc
>>>> *
>>>> * Instead of creating a new index to cover planes and crtc, using
>>>> @@ -484,6 +485,12 @@ struct intel_crtc_scaler_state {
>>>> * avilability.
>>>> */
>>>> #define SKL_CRTC_INDEX 31
>>>> +
>>>> + /*
>>>> + * HDMI YCBCR 420 output consume a scaler. So adding a user
>>>> + * for HDMI output 420 requirement.
>>>> + */
>>>> +#define SKL_HDMI_OUTPUT_INDEX 30
>>> I'm not convinced about this. The scaler is still used as a pipe scaler and the
>>> patch even adds a call intel_pch_panel_fitting().
>> This is a special mode usage of scalar defined in the bspec, when we
>> want to run the scalar into 5x3 auto mode for YCBCR444->YCBCR420 scale down.
>> It can be used only when the PIPE_MISC is also programmed to act
>> accordingly. So this is different from using it as a panel fitter, and
>> that's why added
>> a new scalar user all together.
>>>> unsigned scaler_users;
>>>>
>>>> /* scaler used by crtc for panel fitting purpose */
>>>> @@ -1481,6 +1488,7 @@ void intel_mode_from_pipe_config(struct drm_display_mode *mode,
>>>> struct intel_crtc_state *pipe_config);
>>>>
>>>> int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state);
>>>> +int skl_update_scaler_crtc_hdmi_output(struct intel_crtc_state *state);
>>>> int skl_max_scale(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state);
>>>>
>>>> static inline u32 intel_plane_ggtt_offset(const struct intel_plane_state *state)
>>>> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
>>>> index 22da5cd..8d5aa1e 100644
>>>> --- a/drivers/gpu/drm/i915/intel_hdmi.c
>>>> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
>>>> @@ -1415,6 +1415,7 @@ intel_hdmi_compute_ycbcr_config(struct drm_connector_state *conn_state,
>>>> }
>>>>
>>>> if (type == DRM_HDMI_OUTPUT_YCBCR420) {
>>>> + struct intel_crtc *intel_crtc = to_intel_crtc(conn_state->crtc);
>>>>
>>>> /* YCBCR420 TMDS rate requirement is half the pixel clock */
>>>> config->hdmi_output = DRM_HDMI_OUTPUT_YCBCR420;
>>>> @@ -1422,6 +1423,15 @@ intel_hdmi_compute_ycbcr_config(struct drm_connector_state *conn_state,
>>>> *clock_12bpc /= 2;
>>>> *clock_8bpc /= 2;
>>>>
>>>> + /* YCBCR 420 output conversion needs a scaler */
>>>> + if (skl_update_scaler_crtc_hdmi_output(config)) {
>>>> + DRM_ERROR("Scaler allocation for output failed\n");
>>>> + return DRM_HDMI_OUTPUT_INVALID;
>>>> + }
>>>> +
>>>> + /* Bind this scaler to pipe */
>>>> + intel_pch_panel_fitting(intel_crtc, config,
>>>> + DRM_MODE_SCALE_FULLSCREEN);
>>>> }
>>>>
>>>> /* Encoder is capable of this output, lets commit to CRTC */
>>>> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
>>>> index 96c2cbd..b6a32c4 100644
>>>> --- a/drivers/gpu/drm/i915/intel_panel.c
>>>> +++ b/drivers/gpu/drm/i915/intel_panel.c
>>>> @@ -110,7 +110,8 @@ intel_pch_panel_fitting(struct intel_crtc *intel_crtc,
>>>>
>>>> /* Native modes don't need fitting */
>>>> if (adjusted_mode->crtc_hdisplay == pipe_config->pipe_src_w &&
>>>> - adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h)
>>>> + adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h &&
>>>> + pipe_config->hdmi_output != DRM_HDMI_OUTPUT_YCBCR420)
>>> I don't like that the knowledge that YCBCR420 needs the scaler is spread
>>> everywhere, including this function that should only deal with panel fitting. I
>>> would rather add a force parameter to intel_pch_panel_fitting() and
>>> skl_update_scaler() that would mean setup the scaler even if looks like it's not
>>> necessary. That way the hdmi code would just call them with force enabled,
>>> without sprinkling "hdmi_output == YCBCR420" everywhere.
>> As explained in the comment above, its special case usage of pipe
>> scalar, and that's why being checked specifically.
> I'm still not convinced about this. If this is a special scaler mode that is not
> panel fitting, then this should definitely not touch a function in
> intel_panel.c, specially one with "panel fitting" in the name.
>
> My point is, if this is panel fitting, then it should use panel fitting code
> without special casing. If it isn't, then it should have its own code paths. But
> this patch just creates a blurry line where the panel fitting code needs to be
> special cased for when the HDMI output is YCBCR420 and we are *not* actually
> doing panel fitting.
My understanding of the code is (please correct me if that's not) that
any pipe scalar usages we are keeping it at
panel_fitting level, whereas any plane level stuff is called
plane_scalar. As this new user was a usage of pipe_scalar
with a special configuration and setting, I accommodated the code in
panel fitter level. We can also create new code
for it, but that would be unnecessary duplication of code which does the
same thing, isn't it ?
For this usage, we just need to attach a pipe scalar, and then program
the PIPEMISC (which we do in crtc->mode_set). Do you
think its any good reason for write a new code path altogether ?
- Shashank
>
> Ander
>
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