drm/radeon/kms: improve bpc handling (v2)

Improve handling of bpc (bits per color) in radeon.
In most cases we want 8 except for HDMI, DP, LVDS, and eDP.

v2: handle DP better.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Tested-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

5 files changed, 63 insertions, 12 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index b5ff1f7b6f7e..2fab38f5a08e 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -588,8 +588,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
                 if (encoder->crtc == crtc) {
                         radeon_encoder = to_radeon_encoder(encoder);
                         connector = radeon_get_connector_for_encoder(encoder);
-                        /* if (connector && connector->display_info.bpc)
-                                bpc = connector->display_info.bpc; */
+                        bpc = radeon_get_monitor_bpc(connector);
                         encoder_mode = atombios_get_encoder_mode(encoder);
                         is_duallink = radeon_dig_monitor_is_duallink(encoder, mode->clock);
                         if ((radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT | ATOM_DEVICE_DFP_SUPPORT)) ||
@@ -965,9 +964,7 @@ static void atombios_crtc_set_pll(struct drm_crtc *crtc, struct drm_display_mode
                 struct radeon_connector_atom_dig *dig_connector =
                         radeon_connector->con_priv;
                 int dp_clock;
-
-                /* if (connector->display_info.bpc)
-                        bpc = connector->display_info.bpc; */
+                bpc = radeon_get_monitor_bpc(connector);
 
                 switch (encoder_mode) {
                 case ATOM_ENCODER_MODE_DP_MST:
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index c57d85664e77..cadbb107c803 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -405,13 +405,10 @@ static void dp_get_adjust_train(u8 link_status[DP_LINK_STATUS_SIZE],
 /* get bpc from the EDID */
 static int convert_bpc_to_bpp(int bpc)
 {
-#if 0
         if (bpc == 0)
                 return 24;
         else
                 return bpc * 3;
-#endif
-        return 24;
 }
 
 /* get the max pix clock supported by the link rate and lane num */
@@ -463,7 +460,7 @@ static int radeon_dp_get_dp_lane_number(struct drm_connector *connector,
                                         u8 dpcd[DP_DPCD_SIZE],
                                         int pix_clock)
 {
-        int bpp = convert_bpc_to_bpp(connector->display_info.bpc);
+        int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
         int max_link_rate = dp_get_max_link_rate(dpcd);
         int max_lane_num = dp_get_max_lane_number(dpcd);
         int lane_num;
@@ -482,7 +479,7 @@ static int radeon_dp_get_dp_link_clock(struct drm_connector *connector,
                                        u8 dpcd[DP_DPCD_SIZE],
                                        int pix_clock)
 {
-        int bpp = convert_bpc_to_bpp(connector->display_info.bpc);
+        int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
         int lane_num, max_pix_clock;
 
         if (radeon_connector_encoder_get_dp_bridge_encoder_id(connector) ==
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index e607c4d7dd98..06b209b2e229 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -541,7 +541,7 @@ atombios_dig_encoder_setup(struct drm_encoder *encoder, int action, int panel_mo
                 dp_clock = dig_connector->dp_clock;
                 dp_lane_count = dig_connector->dp_lane_count;
                 hpd_id = radeon_connector->hpd.hpd;
-                /* bpc = connector->display_info.bpc; */
+                bpc = radeon_get_monitor_bpc(connector);
         }
 
         /* no dig encoder assigned */
@@ -1159,7 +1159,7 @@ atombios_external_encoder_setup(struct drm_encoder *encoder,
                 dp_lane_count = dig_connector->dp_lane_count;
                 connector_object_id =
                         (radeon_connector->connector_object_id & OBJECT_ID_MASK) >> OBJECT_ID_SHIFT;
-                /* bpc = connector->display_info.bpc; */
+                bpc = radeon_get_monitor_bpc(connector);
         }
 
         memset(&args, 0, sizeof(args));
diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index bd05156edbdb..71fa389e10fe 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -84,6 +84,62 @@ static void radeon_property_change_mode(struct drm_encoder *encoder)
                                          crtc->x, crtc->y, crtc->fb);
         }
 }
+
+int radeon_get_monitor_bpc(struct drm_connector *connector)
+{
+        struct drm_device *dev = connector->dev;
+        struct radeon_device *rdev = dev->dev_private;
+        struct radeon_connector *radeon_connector = to_radeon_connector(connector);
+        struct radeon_connector_atom_dig *dig_connector;
+        int bpc = 8;
+
+        switch (connector->connector_type) {
+        case DRM_MODE_CONNECTOR_DVII:
+        case DRM_MODE_CONNECTOR_HDMIB:
+                if (radeon_connector->use_digital) {
+                        if (drm_detect_hdmi_monitor(radeon_connector->edid)) {
+                                if (connector->display_info.bpc)
+                                        bpc = connector->display_info.bpc;
+                        }
+                }
+                break;
+        case DRM_MODE_CONNECTOR_DVID:
+        case DRM_MODE_CONNECTOR_HDMIA:
+                if (drm_detect_hdmi_monitor(radeon_connector->edid)) {
+                        if (connector->display_info.bpc)
+                                bpc = connector->display_info.bpc;
+                }
+                break;
+        case DRM_MODE_CONNECTOR_DisplayPort:
+                dig_connector = radeon_connector->con_priv;
+                if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
+                    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP) ||
+                    drm_detect_hdmi_monitor(radeon_connector->edid)) {
+                        if (connector->display_info.bpc)
+                                bpc = connector->display_info.bpc;
+                }
+                break;
+        case DRM_MODE_CONNECTOR_eDP:
+        case DRM_MODE_CONNECTOR_LVDS:
+                if (connector->display_info.bpc)
+                        bpc = connector->display_info.bpc;
+                else if (ASIC_IS_DCE41(rdev) || ASIC_IS_DCE5(rdev)) {
+                        struct drm_connector_helper_funcs *connector_funcs =
+                                connector->helper_private;
+                        struct drm_encoder *encoder = connector_funcs->best_encoder(connector);
+                        struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
+                        struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
+
+                        if (dig->lcd_misc & ATOM_PANEL_MISC_V13_6BIT_PER_COLOR)
+                                bpc = 6;
+                        else if (dig->lcd_misc & ATOM_PANEL_MISC_V13_8BIT_PER_COLOR)
+                                bpc = 8;
+                }
+                break;
+        }
+        return bpc;
+}
+
 static void
 radeon_connector_update_scratch_regs(struct drm_connector *connector, enum drm_connector_status status)
 {
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index f7eb5d8b9fd3..b2cca6a2395c 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -476,6 +476,7 @@ extern u16 radeon_encoder_get_dp_bridge_encoder_id(struct drm_encoder *encoder);
 extern u16 radeon_connector_encoder_get_dp_bridge_encoder_id(struct drm_connector *connector);
 extern bool radeon_connector_encoder_is_hbr2(struct drm_connector *connector);
 extern bool radeon_connector_is_dp12_capable(struct drm_connector *connector);
+extern int radeon_get_monitor_bpc(struct drm_connector *connector);
 
 extern void radeon_connector_hotplug(struct drm_connector *connector);
 extern int radeon_dp_mode_valid_helper(struct drm_connector *connector,