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[144.168.56.201]) by smtp.gmail.com with ESMTPSA id e26sm13804358pfj.46.2021.08.22.19.08.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 22 Aug 2021 19:08:26 -0700 (PDT) From: Bin Meng To: Damien Hedde , "Edgar E . Iglesias" , Alistair Francis , Peter Maydell Subject: [PATCH 2/3] hw/char: cadence_uart: Disable transmit when input clock is disabled Date: Mon, 23 Aug 2021 10:08:12 +0800 Message-Id: <20210823020813.25192-3-bmeng.cn@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210823020813.25192-1-bmeng.cn@gmail.com> References: <20210823020813.25192-1-bmeng.cn@gmail.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::52d; envelope-from=bmeng.cn@gmail.com; helo=mail-pg1-x52d.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" At present when input clock is disabled, any character transmitted to tx fifo can still show on the serial line, which is wrong. Fixes: b636db306e06 ("hw/char/cadence_uart: add clock support") Signed-off-by: Bin Meng Reviewed-by: Alistair Francis --- hw/char/cadence_uart.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c index b4b5e8a3ee..154be34992 100644 --- a/hw/char/cadence_uart.c +++ b/hw/char/cadence_uart.c @@ -327,6 +327,11 @@ static gboolean cadence_uart_xmit(void *do_not_use, GIOCondition cond, static void uart_write_tx_fifo(CadenceUARTState *s, const uint8_t *buf, int size) { + /* ignore characters when unclocked or in reset */ + if (!clock_is_enabled(s->refclk) || device_is_in_reset(DEVICE(s))) { + return; + } + if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) { return; }