4.15-stable review patch. If anyone has any objections, please let me know.
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From: Harry Wentland harry.wentland@amd.com
commit caf0a9030d75509f3cacefe466d6d69d26e3dee6 upstream.
There have been many reports of Ellesmere and Baffin systems not being able to drive HDMI 4k60 due to the fact that we check the HDMI_6GB_EN bit from VBIOS table. Windows seems to not have this issue.
On some systems we fail to the encoder cap info from VBIOS. In that case we should default to enabling HDMI6G support.
This was tested by dwagner on https://bugs.freedesktop.org/show_bug.cgi?id=102820
Signed-off-by: Harry Wentland harry.wentland@amd.com Reviewed-by: Roman Li Roman.Li@amd.com Reviewed-by: Tony Cheng Tony.Cheng@amd.com Acked-by: Harry Wentland harry.wentland@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c @@ -683,6 +683,7 @@ void dce110_link_encoder_construct( { struct bp_encoder_cap_info bp_cap_info = {0}; const struct dc_vbios_funcs *bp_funcs = init_data->ctx->dc_bios->funcs; + enum bp_result result = BP_RESULT_OK;
enc110->base.funcs = &dce110_lnk_enc_funcs; enc110->base.ctx = init_data->ctx; @@ -757,15 +758,24 @@ void dce110_link_encoder_construct( enc110->base.preferred_engine = ENGINE_ID_UNKNOWN; }
+ /* default to one to mirror Windows behavior */ + enc110->base.features.flags.bits.HDMI_6GB_EN = 1; + + result = bp_funcs->get_encoder_cap_info(enc110->base.ctx->dc_bios, + enc110->base.id, &bp_cap_info); + /* Override features with DCE-specific values */ - if (BP_RESULT_OK == bp_funcs->get_encoder_cap_info( - enc110->base.ctx->dc_bios, enc110->base.id, - &bp_cap_info)) { + if (BP_RESULT_OK == result) { enc110->base.features.flags.bits.IS_HBR2_CAPABLE = bp_cap_info.DP_HBR2_EN; enc110->base.features.flags.bits.IS_HBR3_CAPABLE = bp_cap_info.DP_HBR3_EN; enc110->base.features.flags.bits.HDMI_6GB_EN = bp_cap_info.HDMI_6GB_EN; + } else { + dm_logger_write(enc110->base.ctx->logger, LOG_WARNING, + "%s: Failed to get encoder_cap_info from VBIOS with error code %d!\n", + __func__, + result); } }