From f53e4a2d4b793838d661e1cb76b9fc237c8e21b8 Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@dell.com>
Date: Mon, 16 Jan 2017 15:37:11 -0600
Subject: [PATCH] trivial: synapticsmst: only enable plugin if kernel support
 is present

---
 plugins/synapticsmst/fu-plugin-synapticsmst.c | 42 +++++++++++++++++--
 plugins/synapticsmst/synapticsmst-common.c    | 19 +--------
 plugins/synapticsmst/synapticsmst-common.h    |  2 -
 3 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/plugins/synapticsmst/fu-plugin-synapticsmst.c b/plugins/synapticsmst/fu-plugin-synapticsmst.c
index b01f1dc3c..e700a42b9 100644
--- a/plugins/synapticsmst/fu-plugin-synapticsmst.c
+++ b/plugins/synapticsmst/fu-plugin-synapticsmst.c
@@ -21,6 +21,7 @@
  */
 
 #include "config.h"
+#include <smbios_c/smbios.h>
 #include "synapticsmst-device.h"
 #include "synapticsmst-common.h"
 #include "fu-plugin-dell.h"
@@ -29,6 +30,40 @@
 
 #define SYNAPTICS_FLASH_MODE_DELAY 2
 
+static gboolean
+synapticsmst_common_check_supported_system (GError **error)
+{
+	gint i;
+	guint8 dell_supported = 0;
+	gboolean kernel_support = FALSE;
+	struct smbios_struct *de_table;
+
+	de_table = smbios_get_next_struct_by_type (0, 0xDE);
+	smbios_struct_get_data (de_table, &(dell_supported), 0x00, sizeof(guint8));
+	if (dell_supported != 0xDE) {
+		g_set_error (error,
+			     G_IO_ERROR,
+			     G_IO_ERROR_INVALID_DATA,
+			     "MST firmware updating not supported by OEM (%x)",
+			     dell_supported);
+		return FALSE;
+	}
+	for (i=0; i<MAX_DP_AUX_NODES; i++) {
+		if (kernel_support)
+			break;
+		kernel_support = g_file_test (synapticsmst_device_aux_node_to_string (i),
+					      G_FILE_TEST_EXISTS);
+	}
+	if (!kernel_support) {
+		g_set_error (error,
+			     G_IO_ERROR,
+			     G_IO_ERROR_INVALID_DATA,
+			     "MST firmware updating not supported, missing kernel support.");
+		return FALSE;
+	}
+	return TRUE;
+}
+
 static gboolean
 fu_synaptics_add_device (FuPlugin *plugin,
 			 SynapticsMSTDevice *device,
@@ -86,9 +121,6 @@ fu_plugin_synapticsmst_enumerate (FuPlugin *plugin,
 	g_autoptr(SynapticsMSTDevice) device = NULL;
 	g_autoptr(FuDevice) dev = NULL;
 
-	if (!synapticsmst_common_check_supported_system (error))
-		return FALSE;
-
 	for (i=0; i<MAX_DP_AUX_NODES; i++) {
 		aux_node = synapticsmst_device_aux_node_to_string (i);
 		dev = fu_plugin_cache_lookup (plugin, aux_node);
@@ -251,6 +283,10 @@ fu_plugin_startup (FuPlugin *plugin, GError **error)
 gboolean
 fu_plugin_coldplug (FuPlugin *plugin, GError **error)
 {
+	/* verify that this is a supported system */
+	if (!synapticsmst_common_check_supported_system (error))
+		return FALSE;
+
 	/* look for host devices or already plugged in dock devices */
 	if (!fu_plugin_synapticsmst_enumerate (plugin, error))
 		g_debug ("SynapticsMST: Error enumerating.");
diff --git a/plugins/synapticsmst/synapticsmst-common.c b/plugins/synapticsmst/synapticsmst-common.c
index ea8668799..4a398aea7 100644
--- a/plugins/synapticsmst/synapticsmst-common.c
+++ b/plugins/synapticsmst/synapticsmst-common.c
@@ -28,9 +28,9 @@
 #include <time.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <smbios_c/smbios.h>
 #include <glib-object.h>
 #include "synapticsmst-common.h"
+#include "synapticsmst-device.h"
 
 #define UNIT_SIZE       32
 #define MAX_WAIT_TIME   3  /* unit : second */
@@ -399,20 +399,3 @@ synapticsmst_common_disable_remote_control (void)
     synapticsmst_common_config_connection (tmp_layer, g_RAD);
     return rc;
 }
-
-gboolean synapticsmst_common_check_supported_system (GError **error)
-{
-    guint8 dell_supported = 0;
-    struct smbios_struct *de_table;
-    de_table = smbios_get_next_struct_by_type (0, 0xDE);
-    smbios_struct_get_data (de_table, &(dell_supported), 0x00, sizeof(guint8));
-    if (dell_supported != 0xDE) {
-        g_set_error (error,
-                 G_IO_ERROR,
-                 G_IO_ERROR_INVALID_DATA,
-                 "SynapticsMST: firmware updating not supported. (%x)",
-                 dell_supported);
-        return FALSE;
-    }
-    return TRUE;
-}
diff --git a/plugins/synapticsmst/synapticsmst-common.h b/plugins/synapticsmst/synapticsmst-common.h
index 6fa8bf507..18c4278a6 100644
--- a/plugins/synapticsmst/synapticsmst-common.h
+++ b/plugins/synapticsmst/synapticsmst-common.h
@@ -107,6 +107,4 @@ guchar		synapticsmst_common_enable_remote_control	(void);
 
 guchar		synapticsmst_common_disable_remote_control	(void);
 
-gboolean	synapticsmst_common_check_supported_system	(GError **error);
-
 #endif /* __SYNAPTICSMST_COMMON_H */