diff --git a/LUFA.pnproj b/LUFA.pnproj
index 554cb518b7..a6bc6065cf 100644
--- a/LUFA.pnproj
+++ b/LUFA.pnproj
@@ -1 +1 @@
-
\ No newline at end of file
+
\ No newline at end of file
diff --git a/LUFA/DoxygenPages/ChangeLog.txt b/LUFA/DoxygenPages/ChangeLog.txt
index c0e73dae5f..1e887f661d 100644
--- a/LUFA/DoxygenPages/ChangeLog.txt
+++ b/LUFA/DoxygenPages/ChangeLog.txt
@@ -34,6 +34,7 @@
* having to reset the Mass Storage interface
* - USB_CONFIG_ATTR_BUSPOWERED constant renamed to USB_CONFIG_ATTR_RESERVED, as this was misnamed (thanks to NXP Semiconductors)
* - Reordered board name definition indexes so that a mispelled BOARD compile option will default to BOARD_USER rather than BOARD_USBKEY
+ * - Altered the HID class driver to only try to construct at maximum one packet per USB frame, to reduce CPU usage
* - Library Applications:
* - Altered the Mass Storage Host LowLevel demo so that SCSI data STALLs from the attached device can be recovered from automatically without
* having to reset the Mass Storage interface
diff --git a/LUFA/Drivers/USB/Class/Device/HIDClassDevice.c b/LUFA/Drivers/USB/Class/Device/HIDClassDevice.c
index d756b092eb..5c8d878e7e 100644
--- a/LUFA/Drivers/USB/Class/Device/HIDClassDevice.c
+++ b/LUFA/Drivers/USB/Class/Device/HIDClassDevice.c
@@ -156,6 +156,9 @@ void HID_Device_USBTask(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo)
if (USB_DeviceState != DEVICE_STATE_Configured)
return;
+ if (HIDInterfaceInfo->State.PrevFrameNum == USB_Device_GetFrameNumber())
+ return;
+
Endpoint_SelectEndpoint(HIDInterfaceInfo->Config.ReportINEndpointNumber);
if (Endpoint_IsReadWriteAllowed())
@@ -190,6 +193,8 @@ void HID_Device_USBTask(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo)
Endpoint_ClearIN();
}
+
+ HIDInterfaceInfo->State.PrevFrameNum = USB_Device_GetFrameNumber();
}
}
diff --git a/LUFA/Drivers/USB/Class/Device/HIDClassDevice.h b/LUFA/Drivers/USB/Class/Device/HIDClassDevice.h
index ab86da452c..95389f3713 100644
--- a/LUFA/Drivers/USB/Class/Device/HIDClassDevice.h
+++ b/LUFA/Drivers/USB/Class/Device/HIDClassDevice.h
@@ -113,6 +113,7 @@
struct
{
bool UsingReportProtocol; /**< Indicates if the HID interface is set to Boot or Report protocol mode. */
+ uint16_t PrevFrameNum; /**< Frame number of the previous HID report packet opportunity. */
uint16_t IdleCount; /**< Report idle period, in milliseconds, set by the host. */
uint16_t IdleMSRemaining; /**< Total number of milliseconds remaining before the idle period elapsed - this
* should be decremented by the user application if non-zero each millisecond. */