X-Git-Url: https://git.ao2.it/libam7xxx.git/blobdiff_plain/14b6a47d284966d034259b433028e25c5adcd9bd..3dcf58dc4693136812e4b3ccba3b0f726c1bf3d2:/src/am7xxx.c

diff --git a/src/am7xxx.c b/src/am7xxx.c
index 114027e..20b0ddf 100644
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -55,6 +55,7 @@ static struct am7xxx_usb_device_descriptor supported_devices[] = {
 struct _am7xxx_device {
 	libusb_device_handle *usb_device;
 	uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
+	am7xxx_context *ctx;
 	am7xxx_device *next;
 };
 
@@ -321,10 +322,18 @@ static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
 	return ret;
 }
 
-static am7xxx_device *add_new_device(am7xxx_device **devices_list)
+static am7xxx_device *add_new_device(am7xxx_context *ctx)
 {
+	am7xxx_device **devices_list;
 	am7xxx_device *new_device;
 
+	if (ctx == NULL) {
+		fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+		return NULL;
+	}
+
+	devices_list = &(ctx->devices_list);
+
 	new_device = malloc(sizeof(*new_device));
 	if (new_device == NULL) {
 		perror("malloc");
@@ -332,6 +341,8 @@ static am7xxx_device *add_new_device(am7xxx_device **devices_list)
 	}
 	memset(new_device, 0, sizeof(*new_device));
 
+	new_device->ctx = ctx;
+
 	if (*devices_list == NULL) {
 		*devices_list = new_device;
 	} else {
@@ -343,12 +354,18 @@ static am7xxx_device *add_new_device(am7xxx_device **devices_list)
 	return new_device;
 }
 
-static am7xxx_device *find_device(am7xxx_device *devices_list,
+static am7xxx_device *find_device(am7xxx_context *ctx,
 				  unsigned int device_index)
 {
 	unsigned int i = 0;
-	am7xxx_device *current = devices_list;
+	am7xxx_device *current;
 
+	if (ctx == NULL) {
+		fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+		return NULL;
+	}
+
+	current = ctx->devices_list;
 	while (current && i++ < device_index)
 		current = current->next;
 
@@ -420,7 +437,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
 					printf("am7xxx device found, index: %d, name: %s\n",
 					       current_index,
 					       supported_devices[j].name);
-					new_device = add_new_device(&(ctx->devices_list));
+					new_device = add_new_device(ctx);
 					if (new_device == NULL) {
 						/* XXX, the caller may want
 						 * to call am7xxx_shutdown() if
@@ -433,7 +450,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
 				} else if (op == SCAN_OP_OPEN_DEVICE &&
 					   current_index == open_device_index) {
 
-					*dev = find_device(ctx->devices_list, open_device_index);
+					*dev = find_device(ctx, open_device_index);
 					if (*dev == NULL) {
 						ret = -ENODEV;
 						goto out;
@@ -464,6 +481,8 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
 		goto out;
 	}
 
+	/* everything went fine when building the device list */
+	ret = 0;
 out:
 	libusb_free_device_list(list, 1);
 	return ret;