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来自TI的ek-tm4c123gxl usb-dev-gamepad CCS示例的这段代码将中断禁用/使能对中的volatile枚举赋值包装为g_iGamepadState。对我来说，它看起来像一个bug;它应该包装发送报告功能USBDHIDGamepadSendReport（）以防止中间发送中断。正如我所假设的那样，它可以防止单个存储指令的中断，这将是多余的。TI的游戏手柄示例项目中断禁用/启用对是否可以完成任何操作？
下面是所有代码引用枚举...
volatile enum {
eStateNotConfigured, // Not yet configured.
eStateIdle, // Connected, not waiting on data to be sent
eStateSuspend, // Suspended
eStateSending // Connected, waiting on data to be sent out
} g_iGamepadState;
...
//*****************************************************************************
//
// Handles asynchronous events from the HID gamepad driver.
//
// \param pvCBData is the event callback pointer provided during
// USBDHIDGamepadInit(). This is a pointer to our gamepad device structure
// (&g_sGamepadDevice).
// \param ui32Event identifies the event we are being called back for.
// \param ui32MsgData is an event-specific value.
// \param pvMsgData is an event-specific pointer.
//
// This function is called by the HID gamepad driver to inform the application
// of particular asynchronous events related to operation of the gamepad HID
// device.
//
// \return Returns 0 in all cases.
//
//*****************************************************************************
uint32_t GamepadHandler(void *pvCBData, uint32_t ui32Event,
uint32_t ui32MsgData, void *pvMsgData) {
switch (ui32Event) {
case USB_EVENT_CONNECTED: {
g_iGamepadState = eStateIdle;
break;
}
case USB_EVENT_DISCONNECTED: {
g_iGamepadState = eStateNotConfigured;
break;
}
case USB_EVENT_TX_COMPLETE: {
g_iGamepadState = eStateIdle;
break;
}
case USB_EVENT_SUSPEND: {
g_iGamepadState = eStateSuspend;
break;
}
case USB_EVENT_RESUME: {
g_iGamepadState = eStateIdle;
break;
}
...
default: {
break;
}
}
return (0);
}
...
int main(void) {
...
// Not configured initially.
g_iGamepadState = eStateNotConfigured;
...
while (1) {
//
// Wait here until USB device is connected to a host.
//
if (g_GamepadState == eStateIdle) {
...
USBDHIDGamepadSendReport(&g_sGamepadDevice, &sReport,
sizeof(sReport));
//
// Now sending data but protect this from an interrupt since
// it can change in interrupt context as well.
//
IntMasterDisable();
g_iGamepadState = eStateSending;
IntMasterEnable();
}
}
}
中断禁用/启用的位置也会引起我的错误。在该示例中，如果在调用USBHIDGamepadSendReport之后但在IntMasterDisable（）之前获得TX_COMPLETE响应的中断，会发生什么情况？你会遇到eStateSending状态。 – Prismatic
@Prismatic通过TI代码，通常最好遵循它们的相同顺序 –
尽管如此，我遇到了一个问题。以他们的例子为例，我的游戏手柄控制器在一段时间后停止工作（而不是一段时间后）。调试器似乎显示它卡在主while循环中。状态不是NotConfigured，Suspend或Idle，所以我猜测它坚持发送。它可能的中断禁用/启用放置不正确，导致我的问题。虽然TI工程师可以在e2e上发布，但可能会更好。 – Prismatic