diff options
| author | Keith Packard <keithp@keithp.com> | 2013-08-17 17:45:06 +0200 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2013-08-17 17:45:06 +0200 |
| commit | 0dd55f66d79f54b450fd8122aecd84d68b810bf4 (patch) | |
| tree | 04f622783a29ea8cee86e1c8a72794765b604e04 | |
| parent | a0dd93ccf0920260b41c4003955617fd0cd1c8b4 (diff) | |
altos: Wake up on LPC usart ISR only once
Instead of waking up after every character, wait until the FIFO is
empty to reduce overhead
Signed-off-by: Keith Packard <keithp@keithp.com>
| -rw-r--r-- | src/lpc/ao_serial_lpc.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/lpc/ao_serial_lpc.c b/src/lpc/ao_serial_lpc.c index d6b0082a..431ae98a 100644 --- a/src/lpc/ao_serial_lpc.c +++ b/src/lpc/ao_serial_lpc.c @@ -49,21 +49,25 @@ _ao_serial_tx_start(void) void lpc_usart_isr(void) { + uint8_t wake_input = 0; (void) lpc_usart.iir_fcr; while (lpc_usart.lsr & (1 << LPC_USART_LSR_RDR)) { char c = lpc_usart.rbr_thr; if (!ao_fifo_full(ao_usart_rx_fifo)) ao_fifo_insert(ao_usart_rx_fifo, c); - ao_wakeup(&ao_usart_rx_fifo); - if (stdin) - ao_wakeup(&ao_stdin_ready); + wake_input = 1; } if (lpc_usart.lsr & (1 << LPC_USART_LSR_THRE)) { ao_usart_tx_avail = LPC_USART_TX_FIFO_SIZE; _ao_serial_tx_start(); ao_wakeup(&ao_usart_tx_fifo); } + if (wake_input) { + ao_wakeup(&ao_usart_rx_fifo); + if (stdin) + ao_wakeup(&ao_stdin_ready); + } } int |