diff options
Diffstat (limited to 'stmhal/usbd_cdc_interface.c')
| -rw-r--r-- | stmhal/usbd_cdc_interface.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/stmhal/usbd_cdc_interface.c b/stmhal/usbd_cdc_interface.c index 61553e27d..801bcb753 100644 --- a/stmhal/usbd_cdc_interface.c +++ b/stmhal/usbd_cdc_interface.c @@ -257,12 +257,10 @@ static int8_t CDC_Itf_Control(uint8_t cmd, uint8_t* pbuf, uint16_t length) { return USBD_OK; } -/** - * @brief TIM period elapsed callback - * @param htim: TIM handle - * @retval None - */ -void USBD_CDC_HAL_TIM_PeriodElapsedCallback(void) { +// This function is called to process outgoing data. We hook directly into the +// SOF (start of frame) callback so that it is called exactly at the time it is +// needed (reducing latency), and often enough (increasing bandwidth). +void HAL_PCD_SOFCallback(PCD_HandleTypeDef *hpcd) { if (!dev_is_connected) { // CDC device is not connected to a host, so we are unable to send any data return; @@ -276,9 +274,8 @@ void USBD_CDC_HAL_TIM_PeriodElapsedCallback(void) { if (UserTxBufPtrOut != UserTxBufPtrOutShadow) { // We have sent data and are waiting for the low-level USB driver to // finish sending it over the USB in-endpoint. - // We have a 15 * 10ms = 150ms timeout - if (UserTxBufPtrWaitCount < 15) { - PCD_HandleTypeDef *hpcd = hUSBDDevice.pData; + // SOF occurs every 1ms, so we have a 150 * 1ms = 150ms timeout + if (UserTxBufPtrWaitCount < 150) { USB_OTG_GlobalTypeDef *USBx = hpcd->Instance; if (USBx_INEP(CDC_IN_EP & 0x7f)->DIEPTSIZ & USB_OTG_DIEPTSIZ_XFRSIZ) { // USB in-endpoint is still reading the data @@ -457,7 +454,7 @@ void USBD_CDC_TxAlways(const uint8_t *buf, uint32_t len) { } // Some unused code that makes sure the low-level USB buffer is drained. - // Waiting for low-level is handled in USBD_CDC_HAL_TIM_PeriodElapsedCallback. + // Waiting for low-level is handled in HAL_PCD_SOFCallback. /* start = HAL_GetTick(); PCD_HandleTypeDef *hpcd = hUSBDDevice.pData; |