X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=hardware%2Fcommon%2Fusb.c;h=6e678fdb401d1d681000fc3a6e273c7374656957;hb=e22aa87808624c86ec52ea8d57d0a6f35c9e018e;hp=64f887de91458c7a0ac75ff6c89168dba5170ff8;hpb=b5328e1dfaf8a03ce503ab89abed0d83c58a7bb2;p=libsigrok.git

diff --git a/hardware/common/usb.c b/hardware/common/usb.c
index 64f887de..6e678fdb 100644
--- a/hardware/common/usb.c
+++ b/hardware/common/usb.c
@@ -33,14 +33,7 @@
 #define SUBCLASS_USBTMC 0x03
 #define USBTMC_USB488   0x01
 
-/* Message logging helpers with subsystem-specific prefix string. */
-#define LOG_PREFIX "usb: "
-#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
-#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
-#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
-#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
-#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
-#define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
+#define LOG_PREFIX "usb"
 
 /**
  * Find USB devices according to a connection string.
@@ -267,8 +260,11 @@ SR_PRIV int usb_callback(int fd, int revents, void *cb_data)
 
 	g_mutex_lock(&ctx->usb_mutex);
 	ret = ctx->usb_cb(fd, revents, ctx->usb_cb_data);
-	ResetEvent(ctx->usb_event);
-	g_mutex_unlock(&ctx->usb_mutex);
+
+	if (ctx->usb_thread_running) {
+		ResetEvent(ctx->usb_event);
+		g_mutex_unlock(&ctx->usb_mutex);
+	}
 
 	return ret;
 }
@@ -277,6 +273,11 @@ SR_PRIV int usb_callback(int fd, int revents, void *cb_data)
 SR_PRIV int usb_source_add(struct sr_context *ctx, int timeout,
 		sr_receive_data_callback_t cb, void *cb_data)
 {
+	if (ctx->usb_source_present) {
+		sr_err("A USB event source is already present.");
+		return SR_ERR;
+	}
+
 #ifdef _WIN32
 	ctx->usb_event = CreateEvent(NULL, TRUE, FALSE, NULL);
 	g_mutex_init(&ctx->usb_mutex);
@@ -296,12 +297,16 @@ SR_PRIV int usb_source_add(struct sr_context *ctx, int timeout,
 		sr_source_add(lupfd[i]->fd, lupfd[i]->events, timeout, cb, cb_data);
 	free(lupfd);
 #endif
+	ctx->usb_source_present = TRUE;
 
 	return SR_OK;
 }
 
 SR_PRIV int usb_source_remove(struct sr_context *ctx)
 {
+	if (!ctx->usb_source_present)
+		return SR_OK;
+
 #ifdef _WIN32
 	ctx->usb_thread_running = FALSE;
 	g_mutex_unlock(&ctx->usb_mutex);
@@ -319,6 +324,7 @@ SR_PRIV int usb_source_remove(struct sr_context *ctx)
 		sr_source_remove(lupfd[i]->fd);
 	free(lupfd);
 #endif
+	ctx->usb_source_present = FALSE;
 
 	return SR_OK;
 }