[v3] drm/i915/hdmi: add debugfs to contorl HDMI bpc

[Lee Shawn C <shawn.c.lee@intel.com>]

While performing HDMI compliance testing, test equipment may request
different bpc output for signal measurement. However, display driver
typically determines the maximum available bpc based on HW bandwidth.

Introduce a new debugfs that allows user to configure dedicated bpc
manually, and making HDMI compliance test much easier.

v2: Using exist variable max_requested_bpc.
v3: Extend "intel_force_link_bpp" to support HDMI as suggested by Imre.

Cc: Shankar Uma <uma.shankar@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Vidya Srinivas <vidya.srinivas@intel.com>
Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
---
 drivers/gpu/drm/i915/display/g4x_hdmi.c      | 5 +----
 drivers/gpu/drm/i915/display/intel_hdmi.c    | 4 ++++
 drivers/gpu/drm/i915/display/intel_link_bw.c | 6 +-----
 3 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/g4x_hdmi.c b/drivers/gpu/drm/i915/display/g4x_hdmi.c
index 108ebd97f9e4..b31fb1e4bc1a 100644
--- a/drivers/gpu/drm/i915/display/g4x_hdmi.c
+++ b/drivers/gpu/drm/i915/display/g4x_hdmi.c
@@ -136,11 +136,8 @@ static int g4x_hdmi_compute_config(struct intel_encoder *encoder,
 	struct intel_atomic_state *state = to_intel_atomic_state(crtc_state->uapi.state);
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 
-	if (HAS_PCH_SPLIT(display)) {
+	if (HAS_PCH_SPLIT(display))
 		crtc_state->has_pch_encoder = true;
-		if (!intel_fdi_compute_pipe_bpp(crtc_state))
-			return -EINVAL;
-	}
 
 	if (display->platform.g4x)
 		crtc_state->has_hdmi_sink = g4x_compute_has_hdmi_sink(state, crtc);
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index cbee628eb26b..027e8ed0cea8 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -55,6 +55,7 @@
 #include "intel_display_regs.h"
 #include "intel_display_types.h"
 #include "intel_dp.h"
+#include "intel_fdi.h"
 #include "intel_gmbus.h"
 #include "intel_hdcp.h"
 #include "intel_hdcp_regs.h"
@@ -2345,6 +2346,9 @@ int intel_hdmi_compute_config(struct intel_encoder *encoder,
 	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK)
 		pipe_config->pixel_multiplier = 2;
 
+	if (!intel_fdi_compute_pipe_bpp(pipe_config))
+		return -EINVAL;
+
 	pipe_config->has_audio =
 		intel_hdmi_has_audio(encoder, pipe_config, conn_state) &&
 		intel_audio_compute_config(encoder, pipe_config, conn_state);
diff --git a/drivers/gpu/drm/i915/display/intel_link_bw.c b/drivers/gpu/drm/i915/display/intel_link_bw.c
index 3caef7f9c7c4..d194a366ff10 100644
--- a/drivers/gpu/drm/i915/display/intel_link_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_link_bw.c
@@ -449,6 +449,7 @@ void intel_link_bw_connector_debugfs_add(struct intel_connector *connector)
 	switch (connector->base.connector_type) {
 	case DRM_MODE_CONNECTOR_DisplayPort:
 	case DRM_MODE_CONNECTOR_eDP:
+	case DRM_MODE_CONNECTOR_HDMIA:
 		break;
 	case DRM_MODE_CONNECTOR_VGA:
 	case DRM_MODE_CONNECTOR_SVIDEO:
@@ -457,11 +458,6 @@ void intel_link_bw_connector_debugfs_add(struct intel_connector *connector)
 		if (HAS_FDI(display))
 			break;
 
-		return;
-	case DRM_MODE_CONNECTOR_HDMIA:
-		if (HAS_FDI(display) && !HAS_DDI(display))
-			break;
-
 		return;
 	default:
 		return;
-- 
2.34.1