commit 8ba92cf59335 ("arm64: dts: actions: s700: Add Clock Management Unit") breaks the UART on Cubieboard7-lite (based on S700 SoC), This is due to the fact that generic clk routine clk_disable_unused() disables the gate clks, and that in turns disables OWL UART (but UART driver never enables it). To prove this theory, Andre suggested to use "clk_ignore_unused" in kernel commnd line and it worked (Kernel happily lands into RAMFS world :)). This commit fix this up by adding clk_prepare_enable(). Fixes: 8ba92cf59335 ("arm64: dts: actions: s700: Add Clock Management Unit") Signed-off-by: Amit Singh Tomar <amittomer25@xxxxxxxxx> --- drivers/tty/serial/owl-uart.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c index 42c8cc9..c149f8c3 100644 --- a/drivers/tty/serial/owl-uart.c +++ b/drivers/tty/serial/owl-uart.c @@ -680,6 +680,12 @@ static int owl_uart_probe(struct platform_device *pdev) return PTR_ERR(owl_port->clk); } + ret = clk_prepare_enable(owl_port->clk); + if (ret) { + dev_err(&pdev->dev, "could not enable clk\n"); + return ret; + } + owl_port->port.dev = &pdev->dev; owl_port->port.line = pdev->id; owl_port->port.type = PORT_OWL; @@ -712,6 +718,7 @@ static int owl_uart_remove(struct platform_device *pdev) uart_remove_one_port(&owl_uart_driver, &owl_port->port); owl_uart_ports[pdev->id] = NULL; + clk_disable_unprepare(owl_port->clk); return 0; } -- 2.7.4