On Mon, Sep 21, 2015 at 1:53 PM, Lucas Stach [off-list ref] wrote:

Both earlycon and eralyprintk depend on the bootloader setup UART

s/eralyprintk/earlyprintk

clocks being retained. This patch adds the common logic to detect such
situations and make the information available to the clock drivers, as
well as adding the facilities to disable those clocks at the end of
the kernel init.

+void __init imx_register_uart_clocks(struct clk ** const clks[])
+{
+       if (imx_keep_uart_clocks) {
+               int i;
+
+               imx_uart_clocks = clks;
+               for (i = 0; imx_uart_clocks[i]; i++)
+                       clk_prepare_enable(*imx_uart_clocks[i]);

It would be better to check the return value from clk_prepare_enable()
and propagate it in the case of error.

+
+static int __init imx_clk_disable_uart(void)
+{
+       if (imx_keep_uart_clocks && imx_uart_clocks) {
+               int i;
+
+               for (i = 0; imx_uart_clocks[i]; i++)
+                       clk_disable_unprepare(*imx_uart_clocks[i]);
+       }
+
+       return 0;

This function could be made 'void' instead.