From: Uwe Hermann <redacted>
Date: Sun, 18 Mar 2012 11:57:34 +0000 (+0100)
Subject: sr: Fix handling of virtual devices.
X-Git-Tag: libsigrok-0.1.0~40
X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=commitdiff_plain;h=d6eb0c333c8424d151637c18e1a1aef849d5fb31

sr: Fix handling of virtual devices.

I.e., handling of sessions which use input from files (not from actual
logic analyzer hardware).
---

diff --git a/device.c b/device.c
index 3166ea8e..ba29adb5 100644
--- a/device.c
+++ b/device.c
@@ -372,13 +372,20 @@ SR_API gboolean sr_dev_has_hwcap(const struct sr_dev *dev, int hwcap)
 {
 	int *hwcaps, i;
 
+	sr_spew("dev: %s: requesting hwcap %d", __func__, hwcap);
+
 	if (!dev) {
 		sr_err("dev: %s: dev was NULL", __func__);
 		return FALSE; /* TODO: SR_ERR_ARG. */
 	}
 
+	/*
+	 * Virtual devices (which have dev->driver set to NULL) always say that
+	 * they don't have the capability (they can't call hwcap_get_all()).
+	 */
 	if (!dev->driver) {
-		sr_err("dev: %s: dev->driver was NULL", __func__);
+		sr_dbg("dev: %s: dev->driver was NULL, this seems to be "
+		       "a virtual device without capabilities", __func__);
 		return FALSE; /* TODO: SR_ERR_ARG. */
 	}
 
diff --git a/session.c b/session.c
index 8687f432..ffa7e072 100644
--- a/session.c
+++ b/session.c
@@ -127,22 +127,27 @@ SR_API int sr_session_dev_add(struct sr_dev *dev)
 		return SR_ERR_ARG;
 	}
 
+	if (!session) {
+		sr_err("session: %s: session was NULL", __func__);
+		return SR_ERR_BUG;
+	}
+
+	/* If dev->driver is NULL, this is a virtual device. */
 	if (!dev->driver) {
-		sr_err("session: %s: dev->driver was NULL", __func__);
-		return SR_ERR_ARG;
+		sr_dbg("session: %s: dev->driver was NULL, this seems to be "
+		       "a virtual device; continuing", __func__);
+		/* Just add the device, don't run dev_open(). */
+		session->devs = g_slist_append(session->devs, dev);
+		return SR_OK;
 	}
 
+	/* dev->driver is non-NULL (i.e. we have a real device). */
 	if (!dev->driver->dev_open) {
 		sr_err("session: %s: dev->driver->dev_open was NULL",
 		       __func__);
 		return SR_ERR_ARG;
 	}
 
-	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
-		return SR_ERR_BUG;
-	}
-
 	if ((ret = dev->driver->dev_open(dev->driver_index)) != SR_OK) {
 		sr_err("session: %s: dev_open failed (%d)", __func__, ret);
 		return ret;
@@ -438,11 +443,6 @@ SR_PRIV int sr_session_send(struct sr_dev *dev,
 		return SR_ERR_ARG;
 	}
 
-	if (!dev->driver) {
-		sr_err("session: %s: dev->driver was NULL", __func__);
-		return SR_ERR_ARG;
-	}
-
 	if (!packet) {
 		sr_err("session: %s: packet was NULL", __func__);
 		return SR_ERR_ARG;