serial: tegra: Add missing clk_disable_unprepare() in tegra_uart_hw_init()

Add the missing clk_disable_unprepare() before return from
tegra_uart_hw_init() in the error handling path.
When request_irq() fails in tegra_uart_startup(), 'tup->uart_clk'
has been enabled, fix it by adding clk_disable_unprepare().

Fixes: cc9ca4d95846 ("serial: tegra: Only print FIFO error message when an error occurs")
Fixes: d781ec21bae6 ("serial: tegra: report clk rate errors")
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Link: https://lore.kernel.org/r/20221126020852.113378-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index e5b9773..1cf08b3 100644 (file)
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -1046,6 +1046,7 @@ static int tegra_uart_hw_init(struct tegra_uart_port *tup)
        if (tup->cdata->fifo_mode_enable_status) {
                ret = tegra_uart_wait_fifo_mode_enabled(tup);
                if (ret < 0) {
+                       clk_disable_unprepare(tup->uart_clk);
                        dev_err(tup->uport.dev,
                                "Failed to enable FIFO mode: %d\n", ret);
                        return ret;
@@ -1067,6 +1068,7 @@ static int tegra_uart_hw_init(struct tegra_uart_port *tup)
         */
        ret = tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD);
        if (ret < 0) {
+               clk_disable_unprepare(tup->uart_clk);
                dev_err(tup->uport.dev, "Failed to set baud rate\n");
                return ret;
        }
@@ -1226,10 +1228,13 @@ static int tegra_uart_startup(struct uart_port *u)
                                dev_name(u->dev), tup);
        if (ret < 0) {
                dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
-               goto fail_hw_init;
+               goto fail_request_irq;
        }
        return 0;
 
+fail_request_irq:
+       /* tup->uart_clk is already enabled in tegra_uart_hw_init */
+       clk_disable_unprepare(tup->uart_clk);
 fail_hw_init:
        if (!tup->use_rx_pio)
                tegra_uart_dma_channel_free(tup, true);