Merge pull request #1255 from cmaglie/usbcdc-loopback-fix

Fixed SerialUSB data handshake when host sends a lot of data (PeterVH, stimmer)
This commit is contained in:
Cristian Maglie 2013-02-06 03:30:12 -08:00
commit 6b25f0c0ba
3 changed files with 29 additions and 7 deletions

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@ -23,8 +23,9 @@ ARDUINO 1.5.2 BETA - 2012.01.23
* sam: fixed BSoD on some Windows machine (louismdavis)
* sam: added CANRX1/CANTX1 pins 88/89 (same physical pin for 66/53)
* sam: fixed analogWrite when used in very thight write loops (V.Dorrich)
* sam: fixed USBSerial.write() while sending big buffers (Bill Dreschel)
* sam: USBSerial receive buffer size is now 512 (PeterVH)
* sam: fixed SerialUSB.write() while sending big buffers (Bill Dreschel)
* sam: SerialUSB receive buffer size is now 512 (PeterVH)
* sam: Fixed SerialUSB data handshake when host sends a lot of data (PeterVH, stimmer)
[libraries]
* sam: Added Servo library

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@ -155,18 +155,39 @@ void Serial_::end(void)
void Serial_::accept(void)
{
static uint32_t guard = 0;
// synchronized access to guard
do {
if (__LDREXW(&guard) != 0) {
__CLREX();
return; // busy
}
} while (__STREXW(1, &guard) != 0); // retry until write succeed
ring_buffer *buffer = &cdc_rx_buffer;
uint32_t c = USBD_Recv(CDC_RX);
uint32_t i = (uint32_t)(buffer->head+1) % CDC_SERIAL_BUFFER_SIZE;
// if we should be storing the received character into the location
// just before the tail (meaning that the head would advance to the
// current location of the tail), we're about to overflow the buffer
// and so we don't write the character or advance the head.
if (i != buffer->tail) {
while (i != buffer->tail) {
uint32_t c;
if (!USBD_Available(CDC_RX)) {
udd_ack_fifocon(CDC_RX);
break;
}
c = USBD_Recv(CDC_RX);
// c = UDD_Recv8(CDC_RX & 0xF);
buffer->buffer[buffer->head] = c;
buffer->head = i;
i = (i + 1) % CDC_SERIAL_BUFFER_SIZE;
}
// release the guard
guard = 0;
}
int Serial_::available(void)
@ -202,6 +223,8 @@ int Serial_::read(void)
{
unsigned char c = buffer->buffer[buffer->tail];
buffer->tail = (unsigned int)(buffer->tail + 1) % CDC_SERIAL_BUFFER_SIZE;
if (USBD_Available(CDC_RX))
accept();
return c;
}
}

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@ -601,10 +601,8 @@ static void USB_ISR(void)
udd_ack_out_received(CDC_RX);
// Handle received bytes
while (USBD_Available(CDC_RX))
if (USBD_Available(CDC_RX))
SerialUSB.accept();
udd_ack_fifocon(CDC_RX);
}
if (Is_udd_sof())