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usart_fill_rxfifo: fetch no more than available room in FIFO

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Philippe Teuwen 2019-04-23 00:25:14 +02:00
parent 268ca8294e
commit dda63f9556
1 changed files with 37 additions and 16 deletions
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53
common/usart.c
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@ -48,27 +48,48 @@ static size_t us_rxfifo_high = 0;
static void usart_fill_rxfifo(void) { static void usart_fill_rxfifo(void) {
uint16_t rxfifo_free = 0;
if (pUS1->US_RNCR == 0) { // One buffer got filled, backup buffer being used if (pUS1->US_RNCR == 0) { // One buffer got filled, backup buffer being used
// TODO check if we have room... if (us_rxfifo_low > us_rxfifo_high)
uint16_t available = USART_BUFFLEN - usart_cur_inbuf_off; rxfifo_free = us_rxfifo_low - us_rxfifo_high;
for (uint16_t i = 0; i < available; i++) {
us_rxfifo[us_rxfifo_high++] = usart_cur_inbuf[usart_cur_inbuf_off + i];
if (us_rxfifo_high == sizeof(us_rxfifo))
us_rxfifo_high = 0;
}
// Give next buffer
pUS1->US_RNPR = (uint32_t)usart_cur_inbuf;
pUS1->US_RNCR = USART_BUFFLEN;
// Swap current buff
if (usart_cur_inbuf == us_inbuf1)
usart_cur_inbuf = us_inbuf2;
else else
usart_cur_inbuf = us_inbuf1; rxfifo_free = sizeof(us_rxfifo) - us_rxfifo_high + us_rxfifo_low;
usart_cur_inbuf_off = 0; uint16_t available = USART_BUFFLEN - usart_cur_inbuf_off;
if (available <= rxfifo_free) {
for (uint16_t i = 0; i < available; i++) {
us_rxfifo[us_rxfifo_high++] = usart_cur_inbuf[usart_cur_inbuf_off + i];
if (us_rxfifo_high == sizeof(us_rxfifo))
us_rxfifo_high = 0;
}
// Give next buffer
pUS1->US_RNPR = (uint32_t)usart_cur_inbuf;
pUS1->US_RNCR = USART_BUFFLEN;
// Swap current buff
if (usart_cur_inbuf == us_inbuf1)
usart_cur_inbuf = us_inbuf2;
else
usart_cur_inbuf = us_inbuf1;
usart_cur_inbuf_off = 0;
} else {
// Take only what we have room for
available = rxfifo_free;
for (uint16_t i = 0; i < available; i++) {
us_rxfifo[us_rxfifo_high++] = usart_cur_inbuf[usart_cur_inbuf_off + i];
if (us_rxfifo_high == sizeof(us_rxfifo))
us_rxfifo_high = 0;
}
usart_cur_inbuf_off += available;
return;
}
} }
if (pUS1->US_RCR < USART_BUFFLEN - usart_cur_inbuf_off) { // Current buffer partially filled if (pUS1->US_RCR < USART_BUFFLEN - usart_cur_inbuf_off) { // Current buffer partially filled
if (us_rxfifo_low > us_rxfifo_high)
rxfifo_free = us_rxfifo_low - us_rxfifo_high;
else
rxfifo_free = sizeof(us_rxfifo) - us_rxfifo_high + us_rxfifo_low;
uint16_t available = USART_BUFFLEN - pUS1->US_RCR - usart_cur_inbuf_off; uint16_t available = USART_BUFFLEN - pUS1->US_RCR - usart_cur_inbuf_off;
// TODO check if we have room... if (available > rxfifo_free)
available = rxfifo_free;
for (uint16_t i = 0; i < available; i++) { for (uint16_t i = 0; i < available; i++) {
us_rxfifo[us_rxfifo_high++] = usart_cur_inbuf[usart_cur_inbuf_off + i]; us_rxfifo[us_rxfifo_high++] = usart_cur_inbuf[usart_cur_inbuf_off + i];
if (us_rxfifo_high == sizeof(us_rxfifo)) if (us_rxfifo_high == sizeof(us_rxfifo))