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From 1e397cf81c02d335b31dbdeaf70e28a4cf94143a Mon Sep 17 00:00:00 2001
From: Hersen Wu <hersenxs.wu@amd.com>
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 <hersenxs.wu@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>
---
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
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