drm : apple: iomfb: Handle OOB ASYNC/CB context

Only observed with dcp/dptx in linux after initialisation and reset in
m1n1. On the initial startup dcp sends two D576 (hotPlug_notify_gated)
presumendly due to state confusion due to  the multiple dptx
connections.

Signed-off-by: Janne Grunau <[email protected]>

Author: jannau

drivers/gpu/drm/apple/dcp-internal.h

@@ -154,7 +154,7 @@ struct apple_dcp {
 	struct dcp_mem_descriptor memdesc[DCP_MAX_MAPPINGS];
 
 	struct dcp_channel ch_cmd, ch_oobcmd;
-	struct dcp_channel ch_cb, ch_oobcb, ch_async;
+	struct dcp_channel ch_cb, ch_oobcb, ch_async, ch_oobasync;
 
 	/* iomfb EP callback handlers */
 	const iomfb_cb_handler *cb_handlers;

drivers/gpu/drm/apple/iomfb.c

@@ -48,6 +48,8 @@ static int dcp_channel_offset(enum dcp_context_id id)
 	switch (id) {
 	case DCP_CONTEXT_ASYNC:
 		return 0x40000;
+	case DCP_CONTEXT_OOBASYNC:
+		return 0x48000;
 	case DCP_CONTEXT_CB:
 		return 0x60000;
 	case DCP_CONTEXT_OOBCB:
@@ -117,6 +119,8 @@ static struct dcp_channel *dcp_get_channel(struct apple_dcp *dcp,
 		return &dcp->ch_oobcmd;
 	case DCP_CONTEXT_ASYNC:
 		return &dcp->ch_async;
+	case DCP_CONTEXT_OOBASYNC:
+		return &dcp->ch_oobasync;
 	default:
 		return NULL;
 	}

drivers/gpu/drm/apple/iomfb.h

@@ -28,6 +28,9 @@ enum dcp_context_id {
 	/* Out-of-band command */
 	DCP_CONTEXT_OOBCMD = 6,
 
+	/* Out-of-band Asynchronous */
+	DCP_CONTEXT_OOBASYNC = 7,
+
 	DCP_NUM_CONTEXTS
 };