From d357b74493c737a51f6a81dcaf30b4433ce22af0 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Samuel=20R=C3=B8dal?= <samuel.rodal@nokia.com>
Date: Fri, 13 Apr 2012 20:31:41 +0200
Subject: [PATCH] Fixed broken logic in evdev input plugins.

If we do multiple reads we need to accumulate the total amount of bytes
read, instead of just taking the last read amount into account.

Change-Id: Iaa9b90c269f3ed9d09dae67452ca816d9db6217f
Reviewed-by: Johannes Zellner <johannes.zellner@nokia.com>
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>
---
 .../evdevkeyboard/qevdevkeyboardhandler.cpp        | 18 +++++++-----
 .../generic/evdevmouse/qevdevmousehandler.cpp      | 18 +++++++-----
 src/plugins/generic/evdevtouch/qevdevtouch.cpp     | 34 ++++++++++++----------
 3 files changed, 41 insertions(+), 29 deletions(-)

diff --git a/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp b/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp
index 73aa641..eb29b85 100644
--- a/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp
+++ b/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp
@@ -168,16 +168,20 @@ void QEvdevKeyboardHandler::readKeycode()
     int n = 0;
 
     forever {
-        n = qt_safe_read(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
+        int result = qt_safe_read(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
 
-        if (n == 0) {
+        if (result == 0) {
             qWarning("Got EOF from the input device.");
             return;
-        } else if (n < 0 && (errno != EINTR && errno != EAGAIN)) {
-           qWarning("Could not read from input device: %s", strerror(errno));
-            return;
-        } else if (n % sizeof(buffer[0]) == 0) {
-            break;
+        } else if (result < 0) {
+            if (errno != EINTR && errno != EAGAIN) {
+                qWarning("Could not read from input device: %s", strerror(errno));
+                return;
+            }
+        } else {
+            n += result;
+            if (n % sizeof(buffer[0]) == 0)
+                break;
         }
     }
 
diff --git a/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp b/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp
index 7c05e9f..5e2911a 100644
--- a/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp
+++ b/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp
@@ -145,16 +145,20 @@ void QEvdevMouseHandler::readMouseData()
     bool pendingMouseEvent = false;
     int eventCompressCount = 0;
     forever {
-        n = QT_READ(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
+        int result = QT_READ(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
 
-        if (n == 0) {
+        if (result == 0) {
             qWarning("Got EOF from the input device.");
             return;
-        } else if (n < 0 && (errno != EINTR && errno != EAGAIN)) {
-            qWarning("Could not read from input device: %s", strerror(errno));
-            return;
-        } else if (n % sizeof(buffer[0]) == 0) {
-            break;
+        } else if (result < 0) {
+            if (errno != EINTR && errno != EAGAIN) {
+                qWarning("Could not read from input device: %s", strerror(errno));
+                return;
+            }
+        } else {
+            n += result;
+            if (n % sizeof(buffer[0]) == 0)
+                break;
         }
     }
 
diff --git a/src/plugins/generic/evdevtouch/qevdevtouch.cpp b/src/plugins/generic/evdevtouch/qevdevtouch.cpp
index c9c4983..1c3e895 100644
--- a/src/plugins/generic/evdevtouch/qevdevtouch.cpp
+++ b/src/plugins/generic/evdevtouch/qevdevtouch.cpp
@@ -253,26 +253,30 @@ void QTouchScreenHandler::readData()
     int n = 0;
     for (; ;) {
 #ifdef USE_MTDEV
-        n = mtdev_get(m_mtdev, m_fd, buffer, sizeof(buffer) / sizeof(::input_event));
-        if (n > 0)
-            n *= sizeof(::input_event);
+        int result = mtdev_get(m_mtdev, m_fd, buffer, sizeof(buffer) / sizeof(::input_event));
+        if (result > 0)
+            result *= sizeof(::input_event);
 #else
-        n = QT_READ(m_fd, reinterpret_cast<char*>(buffer) + n, sizeof(buffer) - n);
+        int result = QT_READ(m_fd, reinterpret_cast<char*>(buffer) + n, sizeof(buffer) - n);
 #endif
-        if (!n) {
+        if (!result) {
             qWarning("Got EOF from input device");
             return;
-        } else if (n < 0 && (errno != EINTR && errno != EAGAIN)) {
-            qWarning("Could not read from input device: %s", strerror(errno));
-            if (errno == ENODEV) { // device got disconnected -> stop reading
-                delete m_notify;
-                m_notify = 0;
-                QT_CLOSE(m_fd);
-                m_fd = -1;
+        } else if (result < 0) {
+            if (errno != EINTR && errno != EAGAIN) {
+                qWarning("Could not read from input device: %s", strerror(errno));
+                if (errno == ENODEV) { // device got disconnected -> stop reading
+                    delete m_notify;
+                    m_notify = 0;
+                    QT_CLOSE(m_fd);
+                    m_fd = -1;
+                }
+                return;
             }
-            return;
-        } else if (n % sizeof(::input_event) == 0) {
-            break;
+        } else {
+            n += result;
+            if (n % sizeof(::input_event) == 0)
+                break;
         }
     }
 
-- 
2.7.4