Hello Lucas, On Mon, Sep 07, 2015 at 05:09:26PM +0200, Lucas Stach wrote: > Both earlycon and earlyprintk depend on the bootloader setup UART > 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. > > Signed-off-by: Lucas Stach <[email protected]> > --- > drivers/clk/imx/clk.c | 38 ++++++++++++++++++++++++++++++++++++++ > drivers/clk/imx/clk.h | 1 + > 2 files changed, 39 insertions(+) > > diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c > index df12b5307175..45a073dab435 100644 > --- a/drivers/clk/imx/clk.c > +++ b/drivers/clk/imx/clk.c > @@ -73,3 +73,41 @@ void imx_cscmr1_fixup(u32 *val) > *val ^= CSCMR1_FIXUP; > return; > } > + > +static int imx_keep_uart_clocks __initdata; > +static struct clk ** const *imx_uart_clocks __initdata; > + > +static int __init imx_keep_uart_clocks_param(char *str) > +{ > + imx_keep_uart_clocks = 1; > + > + return 0; > +} > +__setup_param("earlycon", imx_keep_uart_earlycon, > + imx_keep_uart_clocks_param, 0); > +__setup_param("earlyprintk", imx_keep_uart_earlyprintk, > + imx_keep_uart_clocks_param, 0); > + > +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]); > + } > +} > + > +static int __init imx_clk_disable_uart(void) > +{ > + if (imx_keep_uart_clocks) { > + int i; > + > + for (i = 0; imx_uart_clocks[i]; i++) > + clk_disable_unprepare(*imx_uart_clocks[i]); > + } > + > + return 0; > +} > +late_initcall_sync(imx_clk_disable_uart);
I bet you didn't test if this works when earlyprintk (or earlycon) is provided on the command line but imx_register_uart_clocks isn't called (e.g. because this is a Samsung CPU running a multiarch kernel). Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
