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Commit 97011249 authored by Hersen Wu's avatar Hersen Wu Committed by Alex Deucher
Browse files

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: default avatarHersen Wu <hersenxs.wu@amd.com>
Reviewed-by: default avatarTony Cheng <Tony.Cheng@amd.com>
Acked-by: default avatarHarry Wentland <harry.wentland@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 320a1274

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

+40 −45
Original line number Diff line number Diff line
@@ -1512,7 +1512,7 @@ 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;
@@ -1524,33 +1524,14 @@ 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));



	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__);

	}



	if (irq_reg_rx_power_state == DP_SET_POWER_D0) {



		/*2. Check that Link Status changed, before re-training.*/

	/*1. Check that Link Status changed, before re-training.*/



	/*parse lane status*/

		for (lane = 0;

			lane < link->cur_link_settings.lane_count;

			lane++) {



	for (lane = 0; lane < link->cur_link_settings.lane_count; lane++) {

		/* check status of lanes 0,1

			 * changed DpcdAddress_Lane01Status (0x202)*/

		 * changed DpcdAddress_Lane01Status (0x202)

		 */

		lane_status.raw = get_nibble_at_index(

			&hpd_irq_dpcd_data->bytes.lane01_status.raw,

			lane);
@@ -1561,23 +1542,37 @@ static bool hpd_rx_irq_check_link_loss_status( 
			/* 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*/

			 * dropped) dp sink status has changed

			 */

			sink_status_changed = true;

			break;

		}



	}



	/* Check interlane align.*/

	if (sink_status_changed ||

			!hpd_irq_dpcd_data->bytes.lane_status_updated.bits.

			INTERLANE_ALIGN_DONE) {

		!hpd_irq_dpcd_data->bytes.lane_status_updated.bits.INTERLANE_ALIGN_DONE) {



		dm_logger_write(link->ctx->logger, LOG_HW_HPD_IRQ,

				"%s: Link Status changed.\n",

				__func__);

			"%s: Link Status changed.\n", __func__);



		return_code = true;



		/*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: DPCD read failed to obtain power state.\n",

				__func__);

		} else {

			if (irq_reg_rx_power_state != DP_SET_POWER_D0)

				return_code = false;

		}

	}