diff options
Diffstat (limited to 'chip/g/usart.c')
| -rw-r--r-- | chip/g/usart.c | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/chip/g/usart.c b/chip/g/usart.c index e3e83dd1f2..0a08d261b8 100644 --- a/chip/g/usart.c +++ b/chip/g/usart.c @@ -145,26 +145,29 @@ void get_data_from_usb(struct usart_config const *config) void send_data_to_usb(struct usart_config const *config) { - /* - * UART RX FIFO is 32 bytes in size, let's have little extra room so - * that we could catch up if we are draining the FIFO while the chip - * keeps receiving. - */ - uint8_t buffer[50]; - uint32_t i; - uint32_t room; struct queue const *uart_in = config->producer.queue; int uart = config->uart; + size_t count; + size_t q_room; + size_t tail; + size_t mask; + q_room = queue_space(uart_in); - i = 0; - room = MIN(sizeof(buffer), queue_space(uart_in)); + if (!q_room) + return; - while ((i < room) && uartn_rx_available(uart)) - buffer[i++] = uartn_read_char(uart); + mask = uart_in->buffer_units_mask; + tail = uart_in->state->tail & mask; + count = 0; - if (i) - QUEUE_ADD_UNITS(uart_in, buffer, i); + while ((count != q_room) && uartn_rx_available(uart)) { + uart_in->buffer[tail] = uartn_read_char(uart); + tail = (tail + 1) & mask; + count++; + } + if (count) + queue_advance_tail(uart_in, count); } static void uart_read(struct producer const *producer, size_t count) |