V4L/DVB: pvrusb2: New feature to mark specific hardware support as experimental

This adds a flag in the device attribute structure which can be used
to mark support for a particular device as experimental.  Any devices
flagged in this way, when encountered at run-time, will generate a
warning message to the kernel log.
Signed-off-by: NMike Isely <isely@pobox.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/pvrusb2/pvrusb2-devattr.h

@@ -177,6 +177,11 @@ struct pvr2_device_desc {
 	unsigned int flag_has_composite:1;     /* Has composite input */
 	unsigned int flag_has_svideo:1;        /* Has s-video input */
 	unsigned int flag_fx2_16kb:1;          /* 16KB FX2 firmware OK here */
+
+	/* If this driver is considered experimental, i.e. not all aspects
+	   are working correctly and/or it is untested, mark that fact
+	   with this flag. */
+	unsigned int flag_is_experimental:1;
 };
 
 extern struct usb_device_id pvr2_device_table[];

drivers/media/video/pvrusb2/pvrusb2-hdw.c

@@ -2459,6 +2459,19 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 		   hdw,hdw_desc->description);
 	pvr2_trace(PVR2_TRACE_INFO, "Hardware description: %s",
 		hdw_desc->description);
+	if (hdw_desc->flag_is_experimental) {
+		pvr2_trace(PVR2_TRACE_INFO, "**********");
+		pvr2_trace(PVR2_TRACE_INFO,
+			   "WARNING: Support for this device (%s) is"
+			   " experimental.", hdw_desc->description);
+		pvr2_trace(PVR2_TRACE_INFO,
+			   "Important functionality might not be"
+			   " entirely working.");
+		pvr2_trace(PVR2_TRACE_INFO,
+			   "Please consider contacting the driver author to"
+			   " help with further stabilization of the driver.");
+		pvr2_trace(PVR2_TRACE_INFO, "**********");
+	}
 	if (!hdw) goto fail;
 
 	init_timer(&hdw->quiescent_timer);