Remove no longer needed EventHub usleep() optimization.

This optimization is no longer needed now that the kernel evdev
driver's poll() implementation only wakes up the poll after
the final sync.

Change-Id: If237776861df9cfac3086e744d3bbf3484d4c53b

Author: Jeff Brown

services/input/EventHub.cpp

@@ -156,8 +156,6 @@ EventHub::EventHub(void) :
         mPendingEventCount(0), mPendingEventIndex(0), mPendingINotify(false) {
     acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_ID);
 
-    mNumCpus = sysconf(_SC_NPROCESSORS_ONLN);
-
     mEpollFd = epoll_create(EPOLL_SIZE_HINT);
     LOG_ALWAYS_FATAL_IF(mEpollFd < 0, "Could not create epoll instance.  errno=%d", errno);
 
@@ -775,19 +773,6 @@ size_t EventHub::getEvents(int timeoutMillis, RawEvent* buffer, size_t bufferSiz
         } else {
             // Some events occurred.
             mPendingEventCount = size_t(pollResult);
-
-            // On an SMP system, it is possible for the framework to read input events
-            // faster than the kernel input device driver can produce a complete packet.
-            // Because poll() wakes up as soon as the first input event becomes available,
-            // the framework will often end up reading one event at a time until the
-            // packet is complete.  Instead of one call to read() returning 71 events,
-            // it could take 71 calls to read() each returning 1 event.
-            //
-            // Sleep for a short period of time after waking up from the poll() to give
-            // the kernel time to finish writing the entire packet of input events.
-            if (mNumCpus > 1) {
-                usleep(250);
-            }
         }
     }
 

services/input/EventHub.h

@@ -367,9 +367,6 @@ class EventHub : public EventHubInterface
     size_t mPendingEventCount;
     size_t mPendingEventIndex;
     bool mPendingINotify;
-
-    // Set to the number of CPUs.
-    int32_t mNumCpus;
 };
 
 }; // namespace android