From 1e397cf81c02d335b31dbdeaf70e28a4cf94143a Mon Sep 17 00:00:00 2001 From: Hersen Wu Date: Mon, 20 Nov 2017 12:45:54 -0500 Subject: [PATCH 2832/4131] drm/amd/display: USB-C / thunderbolt dock specific workaround reading dpcd 0x600 cause link loss for a particular USB-C dock with thurderbolt. workaround by avoiding dcpd 0x600 read unless it's necessary. Signed-off-by: Hersen Wu Reviewed-by: Tony Cheng Acked-by: Harry Wentland Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 85 +++++++++++------------- 1 file changed, 40 insertions(+), 45 deletions(-) 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 7962086..00528b2 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 @@ -1509,7 +1509,7 @@ static bool hpd_rx_irq_check_link_loss_status( struct dc_link *link, union hpd_irq_data *hpd_irq_dpcd_data) { - uint8_t irq_reg_rx_power_state; + uint8_t irq_reg_rx_power_state = 0; enum dc_status dpcd_result = DC_ERROR_UNEXPECTED; union lane_status lane_status; uint32_t lane; @@ -1521,60 +1521,55 @@ static bool hpd_rx_irq_check_link_loss_status( if (link->cur_link_settings.lane_count == 0) return return_code; - /*1. Check that we can handle interrupt: Not in FS DOS, - * Not in "Display Timeout" state, Link is trained. - */ - dpcd_result = core_link_read_dpcd(link, - DP_SET_POWER, - &irq_reg_rx_power_state, - sizeof(irq_reg_rx_power_state)); + /*1. Check that Link Status changed, before re-training.*/ - if (dpcd_result != DC_OK) { - irq_reg_rx_power_state = DP_SET_POWER_D0; - dm_logger_write(link->ctx->logger, LOG_HW_HPD_IRQ, - "%s: DPCD read failed to obtain power state.\n", - __func__); + /*parse lane status*/ + for (lane = 0; lane < link->cur_link_settings.lane_count; lane++) { + /* check status of lanes 0,1 + * changed DpcdAddress_Lane01Status (0x202) + */ + lane_status.raw = get_nibble_at_index( + &hpd_irq_dpcd_data->bytes.lane01_status.raw, + lane); + + if (!lane_status.bits.CHANNEL_EQ_DONE_0 || + !lane_status.bits.CR_DONE_0 || + !lane_status.bits.SYMBOL_LOCKED_0) { + /* if one of the channel equalization, clock + * recovery or symbol lock is dropped + * consider it as (link has been + * dropped) dp sink status has changed + */ + sink_status_changed = true; + break; + } } - if (irq_reg_rx_power_state == DP_SET_POWER_D0) { + /* Check interlane align.*/ + if (sink_status_changed || + !hpd_irq_dpcd_data->bytes.lane_status_updated.bits.INTERLANE_ALIGN_DONE) { - /*2. Check that Link Status changed, before re-training.*/ - - /*parse lane status*/ - for (lane = 0; - lane < link->cur_link_settings.lane_count; - lane++) { - - /* check status of lanes 0,1 - * changed DpcdAddress_Lane01Status (0x202)*/ - lane_status.raw = get_nibble_at_index( - &hpd_irq_dpcd_data->bytes.lane01_status.raw, - lane); - - if (!lane_status.bits.CHANNEL_EQ_DONE_0 || - !lane_status.bits.CR_DONE_0 || - !lane_status.bits.SYMBOL_LOCKED_0) { - /* if one of the channel equalization, clock - * recovery or symbol lock is dropped - * consider it as (link has been - * dropped) dp sink status has changed*/ - sink_status_changed = true; - break; - } + dm_logger_write(link->ctx->logger, LOG_HW_HPD_IRQ, + "%s: Link Status changed.\n", __func__); - } + return_code = true; - /* Check interlane align.*/ - if (sink_status_changed || - !hpd_irq_dpcd_data->bytes.lane_status_updated.bits. - INTERLANE_ALIGN_DONE) { + /*2. Check that we can handle interrupt: Not in FS DOS, + * Not in "Display Timeout" state, Link is trained. + */ + dpcd_result = core_link_read_dpcd(link, + DP_SET_POWER, + &irq_reg_rx_power_state, + sizeof(irq_reg_rx_power_state)); + if (dpcd_result != DC_OK) { dm_logger_write(link->ctx->logger, LOG_HW_HPD_IRQ, - "%s: Link Status changed.\n", + "%s: DPCD read failed to obtain power state.\n", __func__); - - return_code = true; + } else { + if (irq_reg_rx_power_state != DP_SET_POWER_D0) + return_code = false; } } -- 2.7.4