From: Frank Chang <frank.chang@sifive.com>
Date: Thu, 11 Sep 2025 16:06:44 +0000 (+0800)
Subject: hw/char: sifive_uart: Avoid pushing Tx FIFO when size is zero
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a090ecd880a1b211e92c41029d1a90edf6686a48;p=thirdparty%2Fqemu.git

hw/char: sifive_uart: Avoid pushing Tx FIFO when size is zero

There's no need to call fifo8_push_all() when size is zero.

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250911160647.5710-3-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---

diff --git a/hw/char/sifive_uart.c b/hw/char/sifive_uart.c
index 138c31fcabf..401f869680d 100644
--- a/hw/char/sifive_uart.c
+++ b/hw/char/sifive_uart.c
@@ -122,7 +122,9 @@ static void sifive_uart_write_tx_fifo(SiFiveUARTState *s, const uint8_t *buf,
         qemu_log_mask(LOG_GUEST_ERROR, "sifive_uart: TX FIFO overflow");
     }
 
-    fifo8_push_all(&s->tx_fifo, buf, size);
+    if (size > 0) {
+        fifo8_push_all(&s->tx_fifo, buf, size);
+    }
 
     if (fifo8_is_full(&s->tx_fifo)) {
         s->txfifo |= SIFIVE_UART_TXFIFO_FULL;