From: Amit Singh Tomar amittomer25@gmail.com
commit abf42d2f333b21bf8d33b2fbb8a85fa62037ac01 upstream.
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@gmail.com Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/1587067917-1400-1-git-send-email-amittomer25@gmail... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/serial/owl-uart.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/drivers/tty/serial/owl-uart.c +++ b/drivers/tty/serial/owl-uart.c @@ -680,6 +680,12 @@ static int owl_uart_probe(struct platfor 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 platfo
uart_remove_one_port(&owl_uart_driver, &owl_port->port); owl_uart_ports[pdev->id] = NULL; + clk_disable_unprepare(owl_port->clk);
return 0; }