drm/amd/display: AUX will exit when HPD LOW detected

This change shorten wait time when HPD LOW. With HPD LOW, without this
change, AUX routine delay is 450us. With this change, it is 42us.

Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.c b/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.c
index bb526ad326e597a449a1c4d38a9fb134e4ba33a7..1d7309611978e9f07162e919879414618c45e4e0 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.c
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.c
@@ -157,6 +157,10 @@ static void process_read_reply(
                        ctx->operation_succeeded = false;
                }
        break;
+       case AUX_TRANSACTION_REPLY_HPD_DISCON:
+               ctx->status = I2CAUX_TRANSACTION_STATUS_FAILED_HPD_DISCON;
+               ctx->operation_succeeded = false;
+       break;
        default:
                ctx->status = I2CAUX_TRANSACTION_STATUS_UNKNOWN;
                ctx->operation_succeeded = false;
@@ -215,6 +219,10 @@ static void process_read_request(
                         * so we should not wait here */
                }
        break;
+       case AUX_CHANNEL_OPERATION_FAILED_HPD_DISCON:
+               ctx->status = I2CAUX_TRANSACTION_STATUS_FAILED_HPD_DISCON;
+               ctx->operation_succeeded = false;
+       break;
        default:
                ctx->status = I2CAUX_TRANSACTION_STATUS_UNKNOWN;
                ctx->operation_succeeded = false;
@@ -370,6 +378,10 @@ static void process_write_reply(
                        ctx->operation_succeeded = false;
                }
        break;
+       case AUX_TRANSACTION_REPLY_HPD_DISCON:
+               ctx->status = I2CAUX_TRANSACTION_STATUS_FAILED_HPD_DISCON;
+               ctx->operation_succeeded = false;
+       break;
        default:
                ctx->status = I2CAUX_TRANSACTION_STATUS_UNKNOWN;
                ctx->operation_succeeded = false;
@@ -422,6 +434,10 @@ static void process_write_request(
                         * so we should not wait here */
                }
        break;
+       case AUX_CHANNEL_OPERATION_FAILED_HPD_DISCON:
+               ctx->status = I2CAUX_TRANSACTION_STATUS_FAILED_HPD_DISCON;
+               ctx->operation_succeeded = false;
+       break;
        default:
                ctx->status = I2CAUX_TRANSACTION_STATUS_UNKNOWN;
                ctx->operation_succeeded = false;

diff --git a/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.h b/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.h
index 8e71324ccb1094435e51d14134c7d42d5a97f163..b9e35d0474c6ad49eb4e671f004efcc3cfad5d69 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.h
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.h
@@ -51,6 +51,8 @@ enum aux_transaction_reply {
        AUX_TRANSACTION_REPLY_I2C_NACK = 0x10,
        AUX_TRANSACTION_REPLY_I2C_DEFER = 0x20,
 
+       AUX_TRANSACTION_REPLY_HPD_DISCON = 0x40,
+
        AUX_TRANSACTION_REPLY_INVALID = 0xFF
 };
 
@@ -64,7 +66,8 @@ enum aux_channel_operation_result {
        AUX_CHANNEL_OPERATION_SUCCEEDED,
        AUX_CHANNEL_OPERATION_FAILED_REASON_UNKNOWN,
        AUX_CHANNEL_OPERATION_FAILED_INVALID_REPLY,
-       AUX_CHANNEL_OPERATION_FAILED_TIMEOUT
+       AUX_CHANNEL_OPERATION_FAILED_TIMEOUT,
+       AUX_CHANNEL_OPERATION_FAILED_HPD_DISCON
 };
 
 struct aux_engine;

diff --git a/drivers/gpu/drm/amd/display/dc/i2caux/dce110/aux_engine_dce110.c b/drivers/gpu/drm/amd/display/dc/i2caux/dce110/aux_engine_dce110.c
index 90535787a46186993ca7cacaa8e7ec3d3b8ab70c..2b927f25937b4f48ccf4abbe6a58a97017041f71 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/i2caux/dce110/aux_engine_dce110.c
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/dce110/aux_engine_dce110.c
@@ -291,6 +291,12 @@ static void process_channel_reply(
        value = REG_GET(AUX_SW_STATUS,
                        AUX_SW_REPLY_BYTE_COUNT, &bytes_replied);
 
+       /* in case HPD is LOW, exit AUX transaction */
+       if ((value & AUX_SW_STATUS__AUX_SW_HPD_DISCON_MASK)) {
+               reply->status = AUX_TRANSACTION_REPLY_HPD_DISCON;
+               return;
+       }
+
        if (bytes_replied) {
                uint32_t reply_result;
 
@@ -347,8 +353,10 @@ static void process_channel_reply(
                 * because there was surely an error that was asserted
                 * that should have been handled
                 * for hot plug case, this could happens*/
-               if (!(value & AUX_SW_STATUS__AUX_SW_HPD_DISCON_MASK))
+               if (!(value & AUX_SW_STATUS__AUX_SW_HPD_DISCON_MASK)) {
+                       reply->status = AUX_TRANSACTION_REPLY_INVALID;
                        ASSERT_CRITICAL(false);
+               }
        }
 }
 
@@ -371,6 +379,10 @@ static enum aux_channel_operation_result get_channel_status(
        value = REG_WAIT(AUX_SW_STATUS, AUX_SW_DONE, 1,
                                10, aux110->timeout_period/10);
 
+       /* in case HPD is LOW, exit AUX transaction */
+       if ((value & AUX_SW_STATUS__AUX_SW_HPD_DISCON_MASK))
+               return AUX_CHANNEL_OPERATION_FAILED_HPD_DISCON;
+
        /* Note that the following bits are set in 'status.bits'
         * during CTS 4.2.1.2 (FW 3.3.1):
         * AUX_SW_RX_MIN_COUNT_VIOL, AUX_SW_RX_INVALID_STOP,
@@ -402,10 +414,10 @@ static enum aux_channel_operation_result get_channel_status(
                        return AUX_CHANNEL_OPERATION_SUCCEEDED;
                }
        } else {
-               /*time_elapsed >= aux_engine->timeout_period */
-               if (!(value & AUX_SW_STATUS__AUX_SW_HPD_DISCON_MASK))
-                       ASSERT_CRITICAL(false);
-
+               /*time_elapsed >= aux_engine->timeout_period
+                *  AUX_SW_STATUS__AUX_SW_HPD_DISCON = at this point
+                */
+               ASSERT_CRITICAL(false);
                return AUX_CHANNEL_OPERATION_FAILED_TIMEOUT;
        }
 }

diff --git a/drivers/gpu/drm/amd/display/dc/i2caux/engine.h b/drivers/gpu/drm/amd/display/dc/i2caux/engine.h
index 33de8a8834dc1a71e9f898b81c6a2818549f13e6..c1109706a880840477ff64636f330c2d2e380b1b 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/i2caux/engine.h
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/engine.h
@@ -53,7 +53,8 @@ enum i2caux_transaction_status {
        I2CAUX_TRANSACTION_STATUS_FAILED_INCOMPLETE,
        I2CAUX_TRANSACTION_STATUS_FAILED_OPERATION,
        I2CAUX_TRANSACTION_STATUS_FAILED_INVALID_OPERATION,
-       I2CAUX_TRANSACTION_STATUS_FAILED_BUFFER_OVERFLOW
+       I2CAUX_TRANSACTION_STATUS_FAILED_BUFFER_OVERFLOW,
+       I2CAUX_TRANSACTION_STATUS_FAILED_HPD_DISCON
 };
 
 struct i2caux_transaction_request {

diff --git a/drivers/gpu/drm/amd/display/include/ddc_service_types.h b/drivers/gpu/drm/amd/display/include/ddc_service_types.h
index 019e7a095ea103062a78fb20d65a8391ff0016fe..d968956a10cd5de232f610a2fe6eaa4028340315 100644 (file)
--- a/drivers/gpu/drm/amd/display/include/ddc_service_types.h
+++ b/drivers/gpu/drm/amd/display/include/ddc_service_types.h
@@ -40,7 +40,8 @@ enum ddc_result {
        DDC_RESULT_FAILED_INCOMPLETE,
        DDC_RESULT_FAILED_OPERATION,
        DDC_RESULT_FAILED_INVALID_OPERATION,
-       DDC_RESULT_FAILED_BUFFER_OVERFLOW
+       DDC_RESULT_FAILED_BUFFER_OVERFLOW,
+       DDC_RESULT_FAILED_HPD_DISCON
 };
 
 enum ddc_service_type {