Revert "drm/amd/display: make dm_dp_aux_transfer return payload bytes instead of size"

This reverts commit cc195141133ac3e767d930bedd8294ceebf1f10b.

This commit was problematic on other OSes. The real solution is to
leave all the error checking to DRM and don't do it in DC, which is
addressed by "Return aux replies directly to DRM" later in this patchset.

v2: Add reason for revert.

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 13 insertions, 3 deletions

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 1d7309611978..0afd2fa57bbe 100644
--- a/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.c
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/aux_engine.c
@@ -128,8 +128,20 @@ static void process_read_reply(
 			ctx->status =
 				I2CAUX_TRANSACTION_STATUS_FAILED_PROTOCOL_ERROR;
 			ctx->operation_succeeded = false;
+		} else if (ctx->returned_byte < ctx->current_read_length) {
+			ctx->current_read_length -= ctx->returned_byte;
+
+			ctx->offset += ctx->returned_byte;
+
+			++ctx->invalid_reply_retry_aux_on_ack;
+
+			if (ctx->invalid_reply_retry_aux_on_ack >
+				AUX_INVALID_REPLY_RETRY_COUNTER) {
+				ctx->status =
+				I2CAUX_TRANSACTION_STATUS_FAILED_PROTOCOL_ERROR;
+				ctx->operation_succeeded = false;
+			}
 		} else {
-			ctx->current_read_length = ctx->returned_byte;
 			ctx->status = I2CAUX_TRANSACTION_STATUS_SUCCEEDED;
 			ctx->transaction_complete = true;
 			ctx->operation_succeeded = true;
@@ -290,7 +302,6 @@ static bool read_command(
 				ctx.operation_succeeded);
 	}
 
-	request->payload.length = ctx.reply.length;
 	return ctx.operation_succeeded;
 }
 
diff --git a/drivers/gpu/drm/amd/display/dc/i2caux/i2caux.c b/drivers/gpu/drm/amd/display/dc/i2caux/i2caux.c
index 14dc8c94d862..9b0bcc6b769b 100644
--- a/drivers/gpu/drm/amd/display/dc/i2caux/i2caux.c
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/i2caux.c
@@ -254,7 +254,6 @@ bool dal_i2caux_submit_aux_command(
 			break;
 		}
 
-		cmd->payloads->length = request.payload.length;
 		++index_of_payload;
 	}