From ee76592482d34c56c17dd8b75bf8e30deeb1e6af Mon Sep 17 00:00:00 2001 From: George Shen Date: Tue, 17 Dec 2019 14:34:33 -0500 Subject: [PATCH] drm/amd/display: Add w/a to reset PHY before link training in verify_link_cap [Why] PHY will sometimes be in bad state on hotplugging display from USB-C dongle. [How] Add additional calls to disable and then enable PHY before link training starts during verify_link_cap. Signed-off-by: George Shen Reviewed-by: Tony Cheng Acked-by: Harry Wentland Acked-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 10 ++++++++++ drivers/gpu/drm/amd/display/dc/dc.h | 1 + drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c | 3 ++- 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index e415f7730f43..75dc387bbb2b 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -1892,6 +1892,16 @@ bool dp_verify_link_cap( /* disable PHY done possible by BIOS, will be done by driver itself */ dp_disable_link_phy(link, link->connector_signal); + /* Temporary Renoir-specific workaround for SWDEV-215184; + * PHY will sometimes be in bad state on hotplugging display from certain USB-C dongle, + * so add extra cycle of enabling and disabling the PHY before first link training. + */ + if (link->link_enc->features.flags.bits.DP_IS_USB_C && + link->dc->debug.usbc_combo_phy_reset_wa) { + dp_enable_link_phy(link, link->connector_signal, dp_cs_id, cur); + dp_disable_link_phy(link, link->connector_signal); + } + dp_cs_id = get_clock_source_id(link); /* link training starts with the maximum common settings diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index ecd2257de80b..8c7ff9e322f1 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -421,6 +421,7 @@ struct dc_debug_options { bool disable_dram_clock_change_vactive_support; bool validate_dml_output; bool enable_dmcub_surface_flip; + bool usbc_combo_phy_reset_wa; }; struct dc_debug_data { diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c index f1ec3448c0c0..0c02120311b6 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c @@ -835,7 +835,8 @@ static const struct dc_debug_options debug_defaults_drv = { .scl_reset_length10 = true, .sanity_checks = true, .disable_48mhz_pwrdwn = false, - .nv12_iflip_vm_wa = true + .nv12_iflip_vm_wa = true, + .usbc_combo_phy_reset_wa = true }; static const struct dc_debug_options debug_defaults_diags = { -- 2.45.2