Hi Uwe, Am Montag, den 07.09.2015, 20:52 +0200 schrieb Uwe Kleine-König: > 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). > Ah, damn! Thanks for spotting.
Regards, Lucas -- Pengutronix e.K. | Lucas Stach | 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
