From: Antonio Ospite <ospite@studenti.unina.it>
Date: Fri, 7 Dec 2012 11:22:45 +0000 (+0100)
Subject: am7xxx: detect unexpected responses to AM7XXX_PACKET_TYPE_DEVINFO requests
X-Git-Tag: v0.1.3~6^2~2
X-Git-Url: https://git.ao2.it/libam7xxx.git/commitdiff_plain/69c8952c3d754f6928f9628e6ce4d7de95fa846d?ds=inline;hp=--cc

am7xxx: detect unexpected responses to AM7XXX_PACKET_TYPE_DEVINFO requests

Under some conditions, some devices like Philips/Sagemcom PPX projectors
return a strangely small packet (e.g. an AM7XXX_PACKET_TYPE_POWER with
header_data_len == 2) in reply to an AM7XXX_PACKET_TYPE_DEVINFO, hence
NOT providing useful device info.
---

69c8952c3d754f6928f9628e6ce4d7de95fa846d
diff --git a/src/am7xxx.c b/src/am7xxx.c
index 47f79ea..bc671f1 100644
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -752,6 +752,13 @@ AM7XXX_PUBLIC int am7xxx_get_device_info(am7xxx_device *dev,
 	if (ret < 0)
 		return ret;
 
+	if (h.packet_type != AM7XXX_PACKET_TYPE_DEVINFO) {
+		error(dev->ctx, "expected packet type: %d, got %d instead!\n",
+		      AM7XXX_PACKET_TYPE_DEVINFO, h.packet_type);
+		errno = ENOTSUP;
+		return -ENOTSUP;
+	}
+
 	device_info->native_width = h.header_data.devinfo.native_width;
 	device_info->native_height = h.header_data.devinfo.native_height;
 #if 0