@@ -229,6 +229,13 @@ static void pl011_loopback_tx(PL011State *s, uint32_t value)
pl011_fifo_rx_put(s, value);
}
+static void pl011_drain_tx(PL011State *s)
+{
+ trace_pl011_fifo_tx_drain(fifo8_num_used(&s->xmit_fifo));
+ pl011_reset_tx_fifo(s);
+ s->rsr &= ~RSR_OE;
+}
+
static gboolean pl011_xmit(void *do_not_use, GIOCondition cond, void *opaque)
{
PL011State *s = opaque;
@@ -242,6 +249,12 @@ static gboolean pl011_xmit(void *do_not_use, GIOCondition cond, void *opaque)
qemu_log_mask(LOG_GUEST_ERROR, "PL011 data written to disabled TX UART\n");
}
+ if (!qemu_chr_fe_backend_connected(&s->chr)) {
+ /* Instant drain the fifo when there's no back-end. */
+ pl011_drain_tx(s);
+ return G_SOURCE_REMOVE;
+ }
+
data = fifo8_pop(&s->xmit_fifo);
bytes_consumed = 1;
@@ -63,6 +63,7 @@ pl011_fifo_rx_full(void) "RX FIFO now full, RXFF set"
pl011_fifo_tx_put(uint8_t byte) "TX FIFO push char [0x%02x]"
pl011_fifo_tx_xmit(int count) "TX FIFO pop %d chars"
pl011_fifo_tx_overrun(void) "TX FIFO overrun"
+pl011_fifo_tx_drain(unsigned drained) "TX FIFO draining %u chars"
pl011_baudrate_change(unsigned int baudrate, uint64_t clock, uint32_t ibrd, uint32_t fbrd) "new baudrate %u (clk: %" PRIu64 "hz, ibrd: %" PRIu32 ", fbrd: %" PRIu32 ")"
# cmsdk-apb-uart.c
When no character backend is connected, the PL011 frontend just drains the FIFO. Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> --- hw/char/pl011.c | 13 +++++++++++++ hw/char/trace-events | 1 + 2 files changed, 14 insertions(+)