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This does not program the PCON or synthesize source-control > FRL state. > > Signed-off-by: Stephen Hi Stephen, thank you for the patch. What dongle you are observing this issue on? We are interested in reproducing the observed bug. Thanks, George > --- > .../display/dc/link/protocols/link_dp_capability.c | 47 ++++++++++++++++++++-- > .../drm/amd/display/include/ddc_service_types.h | 1 + > 2 files changed, 45 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c > index 47abb4066709..c2b48abfe7e6 100644 > --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c > +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c > @@ -1158,6 +1158,31 @@ static void read_and_intersect_post_frl_lt_status( > } > } > > +static bool is_ch7218_pcon(const struct dc_link *link) > +{ > + return link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_2B02F0 && > + !memcmp(link->dpcd_caps.branch_dev_name, "CH7218", > + sizeof(link->dpcd_caps.branch_dev_name)); > +} > + > +static void apply_ch7218_pcon_caps_quirk(struct dc_link *link) > +{ > + if (!link->dc->caps.dp_hdmi21_pcon_support) > + return; > + > + /* > + * Some CH7218 firmware reports no downstream port, or reports the > + * detailed downstream port as DP, while the device identity and EDID > + * describe a DP-to-HDMI 2.1 PCON. Restore only the documented converter > + * capability ceilings here; do not touch the PCON link state. > + */ > + link->dpcd_caps.dongle_caps.dp_hdmi_max_bpc = 12; > + link->dpcd_caps.dongle_caps.dp_hdmi_frl_max_link_bw_in_kbps = 48000000; > + link->dpcd_caps.dongle_caps.is_dp_hdmi_ycbcr422_pass_through = true; > + link->dpcd_caps.dongle_caps.is_dp_hdmi_ycbcr420_pass_through = true; > + link->dpcd_caps.dongle_caps.extendedCapValid = true; > +} > + > static void get_active_converter_info( > uint8_t data, struct dc_link *link) > { > @@ -1166,10 +1191,19 @@ static void get_active_converter_info( > > /* decode converter info*/ > if (!ds_port.fields.PORT_PRESENT) { > - link->dpcd_caps.dongle_type = DISPLAY_DONGLE_NONE; > + if (is_ch7218_pcon(link)) { > + link->dpcd_caps.is_branch_dev = true; > + link->dpcd_caps.dongle_type = > + DISPLAY_DONGLE_DP_HDMI_CONVERTER; > + link->dpcd_caps.dongle_caps.dongle_type = > + link->dpcd_caps.dongle_type; > + apply_ch7218_pcon_caps_quirk(link); > + } else { > + link->dpcd_caps.dongle_type = DISPLAY_DONGLE_NONE; > + link->dpcd_caps.is_branch_dev = false; > + } > set_dongle_type(link->ddc, > link->dpcd_caps.dongle_type); > - link->dpcd_caps.is_branch_dev = false; > return; > } > > @@ -1200,7 +1234,14 @@ static void get_active_converter_info( > switch (port_caps->bits.DWN_STRM_PORTX_TYPE) { > /*Handle DP case as DONGLE_NONE*/ > case DOWN_STREAM_DETAILED_DP: > - link->dpcd_caps.dongle_type = DISPLAY_DONGLE_NONE; > + link->dpcd_caps.dongle_type = is_ch7218_pcon(link) ? > + DISPLAY_DONGLE_DP_HDMI_CONVERTER : > + DISPLAY_DONGLE_NONE; > + link->dpcd_caps.dongle_caps.dongle_type = > + link->dpcd_caps.dongle_type; > + if (link->dpcd_caps.dongle_type == > + DISPLAY_DONGLE_DP_HDMI_CONVERTER) > + apply_ch7218_pcon_caps_quirk(link); > break; > case DOWN_STREAM_DETAILED_VGA: > link->dpcd_caps.dongle_type = > diff --git a/drivers/gpu/drm/amd/display/include/ddc_service_types.h b/drivers/gpu/drm/amd/display/include/ddc_service_types.h > index 53210e3aa0e0..4164f8a5ae56 100644 > --- a/drivers/gpu/drm/amd/display/include/ddc_service_types.h > +++ b/drivers/gpu/drm/amd/display/include/ddc_service_types.h > @@ -37,6 +37,7 @@ > #define DP_BRANCH_DEVICE_ID_001CF8 0x001CF8 > #define DP_BRANCH_DEVICE_ID_0060AD 0x0060AD > #define DP_BRANCH_DEVICE_ID_001FF2 0x001FF2 > +#define DP_BRANCH_DEVICE_ID_2B02F0 0x2B02F0 > #define DP_BRANCH_HW_REV_10 0x10 > #define DP_BRANCH_HW_REV_20 0x20 > >