hw/char: Have FEWatchFunc handlers return G_SOURCE_CONTINUE/REMOVE

GLib recommend to use G_SOURCE_REMOVE / G_SOURCE_CONTINUE
for GSourceFunc callbacks. Our FEWatchFunc is a GSourceFunc
returning such value. Use such definitions which are
"more memorable" [*].

[*] https://docs.gtk.org/glib/callback.SourceFunc.html#return-value

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230705133139.54419-5-philmd@linaro.org>

hw/char/cadence_uart.c

@@ -307,11 +307,11 @@ static gboolean cadence_uart_xmit(void *do_not_use, GIOCondition cond,
     /* instant drain the fifo when there's no back-end */
     if (!qemu_chr_fe_backend_connected(&s->chr)) {
         s->tx_count = 0;
-        return FALSE;
+        return G_SOURCE_REMOVE;
     }
 
     if (!s->tx_count) {
-        return FALSE;
+        return G_SOURCE_REMOVE;
     }
 
     ret = qemu_chr_fe_write(&s->chr, s->tx_fifo, s->tx_count);
@@ -326,12 +326,12 @@ static gboolean cadence_uart_xmit(void *do_not_use, GIOCondition cond,
                                         cadence_uart_xmit, s);
         if (!r) {
             s->tx_count = 0;
-            return FALSE;
+            return G_SOURCE_REMOVE;
         }
     }
 
     uart_update_status(s);
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 static void uart_write_tx_fifo(CadenceUARTState *s, const uint8_t *buf,

hw/char/cmsdk-apb-uart.c

@@ -199,7 +199,7 @@ static gboolean uart_transmit(void *do_not_use, GIOCondition cond, void *opaque)
     s->watch_tag = 0;
 
     if (!(s->ctrl & R_CTRL_TX_EN_MASK) || !(s->state & R_STATE_TXFULL_MASK)) {
-        return FALSE;
+        return G_SOURCE_REMOVE;
     }
 
     ret = qemu_chr_fe_write(&s->chr, &s->txbuf, 1);
@@ -215,7 +215,7 @@ static gboolean uart_transmit(void *do_not_use, GIOCondition cond, void *opaque)
         }
         /* Transmit pending */
         trace_cmsdk_apb_uart_tx_pending();
-        return FALSE;
+        return G_SOURCE_REMOVE;
     }
 
 buffer_drained:
@@ -227,7 +227,7 @@ buffer_drained:
         s->intstatus |= R_INTSTATUS_TX_MASK;
     }
     cmsdk_apb_uart_update(s);
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 static void uart_cancel_transmit(CMSDKAPBUART *s)

hw/char/ibex_uart.c

@@ -147,7 +147,7 @@ static gboolean ibex_uart_xmit(void *do_not_use, GIOCondition cond,
     /* instant drain the fifo when there's no back-end */
     if (!qemu_chr_fe_backend_connected(&s->chr)) {
         s->tx_level = 0;
-        return FALSE;
+        return G_SOURCE_REMOVE;
     }
 
     if (!s->tx_level) {
@@ -156,7 +156,7 @@ static gboolean ibex_uart_xmit(void *do_not_use, GIOCondition cond,
         s->uart_intr_state |= R_INTR_STATE_TX_EMPTY_MASK;
         s->uart_intr_state &= ~R_INTR_STATE_TX_WATERMARK_MASK;
         ibex_uart_update_irqs(s);
-        return FALSE;
+        return G_SOURCE_REMOVE;
     }
 
     ret = qemu_chr_fe_write(&s->chr, s->tx_fifo, s->tx_level);
@@ -171,7 +171,7 @@ static gboolean ibex_uart_xmit(void *do_not_use, GIOCondition cond,
                                         ibex_uart_xmit, s);
         if (!r) {
             s->tx_level = 0;
-            return FALSE;
+            return G_SOURCE_REMOVE;
         }
     }
 
@@ -192,7 +192,7 @@ static gboolean ibex_uart_xmit(void *do_not_use, GIOCondition cond,
     }
 
     ibex_uart_update_irqs(s);
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 static void uart_write_tx_fifo(IbexUartState *s, const uint8_t *buf,

hw/char/nrf51_uart.c

@@ -93,13 +93,13 @@ static gboolean uart_transmit(void *do_not_use, GIOCondition cond, void *opaque)
              */
             goto buffer_drained;
         }
-        return FALSE;
+        return G_SOURCE_REMOVE;
     }
 
 buffer_drained:
     s->reg[R_UART_TXDRDY] = 1;
     s->pending_tx_byte = false;
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 static void uart_cancel_transmit(NRF51UARTState *s)

hw/char/serial.c

@@ -226,7 +226,7 @@ static gboolean serial_watch_cb(void *do_not_use, GIOCondition cond,
     SerialState *s = opaque;
     s->watch_tag = 0;
     serial_xmit(s);
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 static void serial_xmit(SerialState *s)

hw/char/virtio-console.c

@@ -45,7 +45,7 @@ static gboolean chr_write_unblocked(void *do_not_use, GIOCondition cond,
 
     vcon->watch = 0;
     virtio_serial_throttle_port(VIRTIO_SERIAL_PORT(vcon), false);
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 /* Callback function that's called when the guest sends us data */