1 files changed, 401 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
new file mode 100644
index 000000000000..9a832a9ea42d
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
@@ -0,0 +1,401 @@
+/*
+ * Copyright 2022 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+/* FILE POLICY AND INTENDED USAGE:
+ *
+ *
+ */
+
+#include "link_dp_irq_handler.h"
+#include "link_dpcd.h"
+#include "link_dp_training.h"
+#include "link_dp_capability.h"
+#include "link/accessories/link_dp_trace.h"
+#include "dm_helpers.h"
+
+#define DC_LOGGER_INIT(logger)
+
+bool dc_link_check_link_loss_status(
+	struct dc_link *link,
+	union hpd_irq_data *hpd_irq_dpcd_data)
+{
+	uint8_t irq_reg_rx_power_state = 0;
+	enum dc_status dpcd_result = DC_ERROR_UNEXPECTED;
+	union lane_status lane_status;
+	uint32_t lane;
+	bool sink_status_changed;
+	bool return_code;
+
+	sink_status_changed = false;
+	return_code = false;
+
+	if (link->cur_link_settings.lane_count == 0)
+		return return_code;
+
+	/*1. 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 = dp_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;
+		}
+	}
+
+	/* Check interlane align.*/
+	if (sink_status_changed ||
+		!hpd_irq_dpcd_data->bytes.lane_status_updated.bits.INTERLANE_ALIGN_DONE) {
+
+		DC_LOG_HW_HPD_IRQ("%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) {
+			DC_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;
+		}
+	}
+
+	return return_code;
+}
+
+static bool handle_hpd_irq_psr_sink(struct dc_link *link)
+{
+	union dpcd_psr_configuration psr_configuration;
+
+	if (!link->psr_settings.psr_feature_enabled)
+		return false;
+
+	dm_helpers_dp_read_dpcd(
+		link->ctx,
+		link,
+		368,/*DpcdAddress_PSR_Enable_Cfg*/
+		&psr_configuration.raw,
+		sizeof(psr_configuration.raw));
+
+	if (psr_configuration.bits.ENABLE) {
+		unsigned char dpcdbuf[3] = {0};
+		union psr_error_status psr_error_status;
+		union psr_sink_psr_status psr_sink_psr_status;
+
+		dm_helpers_dp_read_dpcd(
+			link->ctx,
+			link,
+			0x2006, /*DpcdAddress_PSR_Error_Status*/
+			(unsigned char *) dpcdbuf,
+			sizeof(dpcdbuf));
+
+		/*DPCD 2006h   ERROR STATUS*/
+		psr_error_status.raw = dpcdbuf[0];
+		/*DPCD 2008h   SINK PANEL SELF REFRESH STATUS*/
+		psr_sink_psr_status.raw = dpcdbuf[2];
+
+		if (psr_error_status.bits.LINK_CRC_ERROR ||
+				psr_error_status.bits.RFB_STORAGE_ERROR ||
+				psr_error_status.bits.VSC_SDP_ERROR) {
+			bool allow_active;
+
+			/* Acknowledge and clear error bits */
+			dm_helpers_dp_write_dpcd(
+				link->ctx,
+				link,
+				8198,/*DpcdAddress_PSR_Error_Status*/
+				&psr_error_status.raw,
+				sizeof(psr_error_status.raw));
+
+			/* PSR error, disable and re-enable PSR */
+			if (link->psr_settings.psr_allow_active) {
+				allow_active = false;
+				dc_link_set_psr_allow_active(link, &allow_active, true, false, NULL);
+				allow_active = true;
+				dc_link_set_psr_allow_active(link, &allow_active, true, false, NULL);
+			}
+
+			return true;
+		} else if (psr_sink_psr_status.bits.SINK_SELF_REFRESH_STATUS ==
+				PSR_SINK_STATE_ACTIVE_DISPLAY_FROM_SINK_RFB){
+			/* No error is detect, PSR is active.
+			 * We should return with IRQ_HPD handled without
+			 * checking for loss of sync since PSR would have
+			 * powered down main link.
+			 */
+			return true;
+		}
+	}
+	return false;
+}
+
+void dc_link_dp_handle_link_loss(struct dc_link *link)
+{
+	int i;
+	struct pipe_ctx *pipe_ctx;
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+		if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link)
+			break;
+	}
+
+	if (pipe_ctx == NULL || pipe_ctx->stream == NULL)
+		return;
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+		if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off &&
+				pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe)
+			core_link_disable_stream(pipe_ctx);
+	}
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+		if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off
+				&& pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe) {
+			// Always use max settings here for DP 1.4a LL Compliance CTS
+			if (link->is_automated) {
+				pipe_ctx->link_config.dp_link_settings.lane_count =
+						link->verified_link_cap.lane_count;
+				pipe_ctx->link_config.dp_link_settings.link_rate =
+						link->verified_link_cap.link_rate;
+				pipe_ctx->link_config.dp_link_settings.link_spread =
+						link->verified_link_cap.link_spread;
+			}
+			core_link_enable_stream(link->dc->current_state, pipe_ctx);
+		}
+	}
+}
+
+enum dc_status dp_read_hpd_rx_irq_data(
+	struct dc_link *link,
+	union hpd_irq_data *irq_data)
+{
+	static enum dc_status retval;
+
+	/* The HW reads 16 bytes from 200h on HPD,
+	 * but if we get an AUX_DEFER, the HW cannot retry
+	 * and this causes the CTS tests 4.3.2.1 - 3.2.4 to
+	 * fail, so we now explicitly read 6 bytes which is
+	 * the req from the above mentioned test cases.
+	 *
+	 * For DP 1.4 we need to read those from 2002h range.
+	 */
+	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_14)
+		retval = core_link_read_dpcd(
+			link,
+			DP_SINK_COUNT,
+			irq_data->raw,
+			sizeof(union hpd_irq_data));
+	else {
+		/* Read 14 bytes in a single read and then copy only the required fields.
+		 * This is more efficient than doing it in two separate AUX reads. */
+
+		uint8_t tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI + 1];
+
+		retval = core_link_read_dpcd(
+			link,
+			DP_SINK_COUNT_ESI,
+			tmp,
+			sizeof(tmp));
+
+		if (retval != DC_OK)
+			return retval;
+
+		irq_data->bytes.sink_cnt.raw = tmp[DP_SINK_COUNT_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.device_service_irq.raw = tmp[DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0 - DP_SINK_COUNT_ESI];
+		irq_data->bytes.lane01_status.raw = tmp[DP_LANE0_1_STATUS_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.lane23_status.raw = tmp[DP_LANE2_3_STATUS_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.lane_status_updated.raw = tmp[DP_LANE_ALIGN_STATUS_UPDATED_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.sink_status.raw = tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI];
+	}
+
+	return retval;
+}
+
+/*************************Short Pulse IRQ***************************/
+bool dc_link_dp_allow_hpd_rx_irq(const struct dc_link *link)
+{
+	/*
+	 * Don't handle RX IRQ unless one of following is met:
+	 * 1) The link is established (cur_link_settings != unknown)
+	 * 2) We know we're dealing with a branch device, SST or MST
+	 */
+
+	if ((link->cur_link_settings.lane_count != LANE_COUNT_UNKNOWN) ||
+		is_dp_branch_device(link))
+		return true;
+
+	return false;
+}
+
+bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd_irq_dpcd_data, bool *out_link_loss,
+							bool defer_handling, bool *has_left_work)
+{
+	union hpd_irq_data hpd_irq_dpcd_data = {0};
+	union device_service_irq device_service_clear = {0};
+	enum dc_status result;
+	bool status = false;
+
+	if (out_link_loss)
+		*out_link_loss = false;
+
+	if (has_left_work)
+		*has_left_work = false;
+	/* For use cases related to down stream connection status change,
+	 * PSR and device auto test, refer to function handle_sst_hpd_irq
+	 * in DAL2.1*/
+
+	DC_LOG_HW_HPD_IRQ("%s: Got short pulse HPD on link %d\n",
+		__func__, link->link_index);
+
+
+	 /* All the "handle_hpd_irq_xxx()" methods
+		 * should be called only after
+		 * dal_dpsst_ls_read_hpd_irq_data
+		 * Order of calls is important too
+		 */
+	result = dp_read_hpd_rx_irq_data(link, &hpd_irq_dpcd_data);
+	if (out_hpd_irq_dpcd_data)
+		*out_hpd_irq_dpcd_data = hpd_irq_dpcd_data;
+
+	if (result != DC_OK) {
+		DC_LOG_HW_HPD_IRQ("%s: DPCD read failed to obtain irq data\n",
+			__func__);
+		return false;
+	}
+
+	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.AUTOMATED_TEST) {
+		// Workaround for DP 1.4a LL Compliance CTS as USB4 has to share encoders unlike DP and USBC
+		link->is_automated = true;
+		device_service_clear.bits.AUTOMATED_TEST = 1;
+		core_link_write_dpcd(
+			link,
+			DP_DEVICE_SERVICE_IRQ_VECTOR,
+			&device_service_clear.raw,
+			sizeof(device_service_clear.raw));
+		device_service_clear.raw = 0;
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		else
+			dc_link_dp_handle_automated_test(link);
+		return false;
+	}
+
+	if (!dc_link_dp_allow_hpd_rx_irq(link)) {
+		DC_LOG_HW_HPD_IRQ("%s: skipping HPD handling on %d\n",
+			__func__, link->link_index);
+		return false;
+	}
+
+	if (handle_hpd_irq_psr_sink(link))
+		/* PSR-related error was detected and handled */
+		return true;
+
+	/* If PSR-related error handled, Main link may be off,
+	 * so do not handle as a normal sink status change interrupt.
+	 */
+
+	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.UP_REQ_MSG_RDY) {
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		return true;
+	}
+
+	/* check if we have MST msg and return since we poll for it */
+	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.DOWN_REP_MSG_RDY) {
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		return false;
+	}
+
+	/* For now we only handle 'Downstream port status' case.
+	 * If we got sink count changed it means
+	 * Downstream port status changed,
+	 * then DM should call DC to do the detection.
+	 * NOTE: Do not handle link loss on eDP since it is internal link*/
+	if ((link->connector_signal != SIGNAL_TYPE_EDP) &&
+		dc_link_check_link_loss_status(
+			link,
+			&hpd_irq_dpcd_data)) {
+		/* Connectivity log: link loss */
+		CONN_DATA_LINK_LOSS(link,
+					hpd_irq_dpcd_data.raw,
+					sizeof(hpd_irq_dpcd_data),
+					"Status: ");
+
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		else
+			dc_link_dp_handle_link_loss(link);
+
+		status = false;
+		if (out_link_loss)
+			*out_link_loss = true;
+
+		dp_trace_link_loss_increment(link);
+	}
+
+	if (link->type == dc_connection_sst_branch &&
+		hpd_irq_dpcd_data.bytes.sink_cnt.bits.SINK_COUNT
+			!= link->dpcd_sink_count)
+		status = true;
+
+	/* reasons for HPD RX:
+	 * 1. Link Loss - ie Re-train the Link
+	 * 2. MST sideband message
+	 * 3. Automated Test - ie. Internal Commit
+	 * 4. CP (copy protection) - (not interesting for DM???)
+	 * 5. DRR
+	 * 6. Downstream Port status changed
+	 * -ie. Detect - this the only one
+	 * which is interesting for DM because
+	 * it must call dc_link_detect.
+	 */
+	return status;
+}
+