Fix another hidapi releated issue.

pbludov · Apr 23, 2017 · bfb2da3 · bfb2da3
1 parent 3e702d3
commit bfb2da3
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Showing 3 changed files with 16 additions and 4 deletions.
diff --git a/libqhid/qhiddevice_hidapi.cpp b/libqhid/qhiddevice_hidapi.cpp
@@ -241,18 +241,24 @@ static void resetDevice(int vendorId, int deviceId)
 }
 #endif
 
+static int hidapiUsed = 0;
+
 QHIDDevicePrivate::QHIDDevicePrivate(QHIDDevice *q_ptr, int vendorId, int deviceId, int usagePage, int usage)
     : device(nullptr)
     , vendorId(vendorId)
     , deviceId(deviceId)
     , q_ptr(q_ptr)
 {
-    if (hid_init() != 0)
+    // Make sure we call hid_init() only once.
+    if (hidapiUsed == 0 && hid_init() != 0)
     {
         qWarning() << "hid_init failed, error" << errno;
         return;
     }
 
+    // Increment hidapi library usage counter.
+    ++hidapiUsed;
+
     int interfaceNumber = -1;
 #ifdef WITH_LIBUSB_1_0
     hidapiMissingFeatures(
@@ -292,12 +298,18 @@ QHIDDevicePrivate::~QHIDDevicePrivate()
         device = nullptr;
 
 #ifdef WITH_LIBUSB_1_0
-        // Until reset the keyboard interface will be ignored by the kernel.
+        // Until reset the keyboard interface will be ignored by the kernel
+        // since the hidapi library does detach the kernel driver and does
+        // not re-attach it back.
         resetDevice(vendorId, deviceId);
 #endif
     }
 
-    hid_exit();
+    // Only the last one should call hid_exit(),
+    if (--hidapiUsed == 0)
+    {
+        hid_exit();
+    }
 }
 
 bool QHIDDevicePrivate::isValid() const

diff --git a/src/ms735.cpp b/src/ms735.cpp
@@ -57,7 +57,6 @@ MS735::MS735(QObject *parent)
     , eventDevice(new QHIDDevice(VENDOR, PRODUCT, EVENT_USAGE_PAGE, EVENT_USAGE, this))
     , monitor(new QHIDMonitor(VENDOR, PRODUCT, this))
     , timerId(0)
-
 {
     connect(monitor, SIGNAL(deviceArrival(QString)), this, SLOT(deviceArrival(QString)));
     connect(monitor, SIGNAL(deviceRemove()), this, SLOT(deviceRemove()));

diff --git a/src/ms735.h b/src/ms735.h
@@ -49,6 +49,7 @@ class MS735 : public QObject
         CmdControl = 0x0C,
         CmdButtons = 0x0D,
         CmdMacro = 0x0F,
+        CmdVersion = 0x10, // 0x91 => 01 01, this may be 1.1 version.
         CmdFlagGet = 0x80,
         CmdPing = CmdBlink | CmdFlagGet,
         CmdGetProfile = CmdProfile | CmdFlagGet,