Re: [PATCH v13 2/2] drm/i915: Allow "max bpc" property to limit pipe_bpp

On Fri, 2018-10-12 at 00:25 -0700, Radhakrishna Sripada wrote:

Use the newly added "max bpc" connector property to limit pipe bpp.

V3: Use drm_connector_state to access the "max bpc" property V4: Initialize the drm property, add suuport to DP(Ville) V5: Use the property in the connector and fix CI failure(Ville) V6: Use the core function to attach max_bpc property, remove the redundant clamping of pipe bpp based on connector info V7: Fix Checkpatch warnings V9: Cleanup connected_sink_max_bpp and fix initial value in DP(Ville) V12: Fix debug message(Ville) V13: Remove the redundant check and simplify the check logic(Stan)

Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Rodrigo Vivi rodrigo.vivi@intel.com Cc: Kishore Kadiyala kishore.kadiyala@intel.com Cc: Manasi Navare manasi.d.navare@intel.com Cc: Stanislav Lisovskiy stanislav.lisovskiy@intel.com Signed-off-by: Radhakrishna Sripada radhakrishna.sripada@intel.com

---

drivers/gpu/drm/i915/intel_display.c | 49 ++++++++++++++++++++----

drivers/gpu/drm/i915/intel_dp.c | 4 +++ drivers/gpu/drm/i915/intel_hdmi.c | 5 ++++ 3 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 980f4ea68e48..0f1f46abe2f5 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -10791,30 +10791,37 @@ static void intel_modeset_update_connector_atomic_state(struct drm_device *dev) drm_connector_list_iter_end(&conn_iter); }

-static void -connected_sink_compute_bpp(struct intel_connector *connector,

• 	   struct intel_crtc_state *pipe_config)
  

+static int +connected_sink_max_bpp(const struct drm_connector_state *conn_state,

•        struct intel_crtc_state *pipe_config)
  

{

• const struct drm_display_info *info = &connector-

...

base.display_info;

• int bpp = pipe_config->pipe_bpp;

• int bpp;
• struct drm_display_info *info = &conn_state->connector-

...

display_info;

• DRM_DEBUG_KMS("[CONNECTOR:%d:%s] checking for sink bpp

constrains\n",

•       connector->base.base.id,
  

•       connector->base.name);
  

• /* Don't use an invalid EDID bpc value */
• if (info->bpc != 0 && info->bpc * 3 < bpp) {

• DRM_DEBUG_KMS("clamping display bpp (was %d) to EDID
  

reported max of %d\n",

• 	      bpp, info->bpc * 3);
  

• pipe_config->pipe_bpp = info->bpc * 3;
  

• switch (conn_state->max_bpc) {
• case 6 ... 7:

• bpp = 6 * 3;
  

• case 8 ... 9:

• bpp = 8 * 3;
  

• break;
  

• case 10 ... 11:

• bpp = 10 * 3;
  

• break;
  

• case 12:

• bpp = 12 * 3;
  

• break;
  

• default:

• return -EINVAL;
  

  }

• /* Clamp bpp to 8 on screens without EDID 1.4 */
• if (info->bpc == 0 && bpp > 24) {

• DRM_DEBUG_KMS("clamping display bpp (was %d) to
  

default limit of 24\n",

• 	      bpp);
  

• pipe_config->pipe_bpp = 24;
  

• if (bpp != pipe_config->pipe_bpp) {

• DRM_DEBUG_KMS("Limiting display bpp to %d instead of
  

Edid bpp "

• 	      "%d, requested bpp %d, max platform
  

bpp %d\n", bpp,

• 	      3 * info->bpc, 3 * conn_state-
  

...

max_requested_bpc,

• 	      pipe_config->pipe_bpp);
  

• pipe_config->pipe_bpp = bpp;
  

  }
• return 0;

That is definitely simplier. However I think there is still one thing: you now assign pipe_bpp to bpp always if they are not equal. However bpp(which is literally max_bpc) is supposed to limit pipe_bpp from above, not from below. What if pipe_bpp < bpp already, then condition will still be executed and then you'll get pipe_bpp set to higher value than it was supposed to. So I guess the condition should be "if (bpp < pipe_config->pipe_bpp)" or simply do pipe_config->pipe_bpp = min(pipe_config->pipe_bpp, bpp) as I said in previous email.

}

static int @@ -10845,8 +10852,8 @@ compute_baseline_pipe_bpp(struct intel_crtc *crtc, if (connector_state->crtc != &crtc->base) continue;

• connected_sink_compute_bpp(to_intel_connector(connec
  

tor),

• 			   pipe_config);
  

• if (connected_sink_max_bpp(connector_state,
  

pipe_config) < 0)

• 	return -EINVAL;
  

  }

  return bpp;

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 13ff89be6ad6..5f594430b2a4 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -5735,6 +5735,10 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect intel_attach_force_audio_property(connector);

intel_attach_broadcast_rgb_property(connector);

• if (HAS_GMCH_DISPLAY(dev_priv))

• drm_connector_attach_max_bpc_property(connector, 6,
  

10);

• else if (INTEL_GEN(dev_priv) >= 5)

• drm_connector_attach_max_bpc_property(connector, 6,
  

12);

if (intel_dp_is_edp(intel_dp)) { u32 allowed_scalers; diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c index 2c53efc463e6..3158ab085a30 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c +++ b/drivers/gpu/drm/i915/intel_hdmi.c @@ -2103,11 +2103,16 @@ static const struct drm_encoder_funcs intel_hdmi_enc_funcs = { static void intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *connector) {

• struct drm_i915_private *dev_priv = to_i915(connector->dev);
• intel_attach_force_audio_property(connector); intel_attach_broadcast_rgb_property(connector); intel_attach_aspect_ratio_property(connector); drm_connector_attach_content_type_property(connector); connector->state->picture_aspect_ratio =

HDMI_PICTURE_ASPECT_NONE;

• if (!HAS_GMCH_DISPLAY(dev_priv))

• drm_connector_attach_max_bpc_property(connector, 8,
  

12); }

/*