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Fix CDC_Send_FreeBytes

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Štěpán Dalecký 2022-07-02 12:03:45 +02:00
parent 4339e4ffd6
commit b6e2790f15
1 changed files with 6 additions and 12 deletions
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18
src/main/vcpf4/usbd_cdc_vcp.c
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@ -44,7 +44,7 @@ __IO uint32_t bDeviceState = UNCONNECTED; /* USB device status */
/* This is the buffer for data received from the MCU to APP (i.e. MCU TX, APP RX) */
extern uint8_t APP_Rx_Buffer[];
extern uint32_t APP_Rx_ptr_out;
extern volatile uint32_t APP_Rx_ptr_out;
/* Increment this buffer position or roll it back to
start address when writing received data
in the buffer APP_Rx_Buffer. */
@ -190,12 +190,8 @@ uint32_t CDC_Send_FreeBytes(void)
{
/*
return the bytes free in the circular buffer
functionally equivalent to:
(APP_Rx_ptr_out > APP_Rx_ptr_in ? APP_Rx_ptr_out - APP_Rx_ptr_in : APP_RX_DATA_SIZE - APP_Rx_ptr_in + APP_Rx_ptr_in)
but without the impact of the condition check.
*/
return ((APP_Rx_ptr_out - APP_Rx_ptr_in) + (-((int)(APP_Rx_ptr_out <= APP_Rx_ptr_in)) & APP_RX_DATA_SIZE)) - 1;
return (APP_Rx_ptr_out > APP_Rx_ptr_in ? APP_Rx_ptr_out - APP_Rx_ptr_in : APP_RX_DATA_SIZE + APP_Rx_ptr_out - APP_Rx_ptr_in);
}
/**
@ -212,15 +208,13 @@ static uint16_t VCP_DataTx(const uint8_t* Buf, uint32_t Len)
could just check for: USB_CDC_ZLP, but better to be safe
and wait for any existing transmission to complete.
*/
while (USB_Tx_State != 0);
for (uint32_t i = 0; i < Len; i++) {
APP_Rx_Buffer[APP_Rx_ptr_in] = Buf[i];
APP_Rx_ptr_in = (APP_Rx_ptr_in + 1) % APP_RX_DATA_SIZE;
while (CDC_Send_FreeBytes() == 0) {
while ((APP_Rx_ptr_in + 1) % APP_RX_DATA_SIZE == APP_Rx_ptr_out || APP_Rx_ptr_out == APP_RX_DATA_SIZE || USB_Tx_State != 0) {
delay(1);
}
APP_Rx_Buffer[APP_Rx_ptr_in] = Buf[i];
APP_Rx_ptr_in = (APP_Rx_ptr_in + 1) % APP_RX_DATA_SIZE;
}
return USBD_OK;