drivers: hv: dxgkrnl: Do not print error messages when virtual GPU is not present

Dxgkrnl prints the error message "Failed to acquire global channel lock"
when a process tries to open the /dev/dxg device and there is no
virtual GPU. This message should not be printed in this scenario.

Signed-off-by: Iouri Tarassov <[email protected]>

Author: Iouri Tarassov

drivers/hv/dxgkrnl/dxgadapter.c

@@ -78,12 +78,12 @@ void dxgadapter_start(struct dxgadapter *adapter)
 
 	/* The global channel is initialized when the first adapter starts */
 	if (!dxgglobal->global_channel_initialized) {
+		dxgglobal->global_channel_initialized = true;
 		ret = dxgglobal_init_global_channel();
 		if (ret) {
 			dxgglobal_destroy_global_channel();
 			return;
 		}
-		dxgglobal->global_channel_initialized = true;
 	}
 
 	/* Initialize vGPU vm bus channel */

drivers/hv/dxgkrnl/dxgmodule.c

@@ -46,9 +46,13 @@ int dxgglobal_acquire_channel_lock(void)
 {
 	struct dxgglobal *dxgglobal = dxggbl();
 
+	if (!dxgglobal->global_channel_initialized)
+		return -ENODEV;
+
 	down_read(&dxgglobal->channel_lock);
 	if (dxgglobal->channel.channel == NULL) {
 		DXG_ERR("Failed to acquire global channel lock");
+		up_read(&dxgglobal->channel_lock);
 		return -ENODEV;
 	} else {
 		return 0;