Hi Jun, On Wed, 27 Mar 2019 at 03:55, Jun Nie <jun....@linaro.org> wrote: > > Lukasz Majewski <lu...@denx.de> 于2019年3月27日周三 下午5:34写道： > > > > Hi Simon, Jun, > > > > > Hi Jun, > > > > > > On Fri, 22 Mar 2019 at 16:02, Jun Nie <jun....@linaro.org> wrote: > > > > > > > > Simon Glass <s...@chromium.org> 于2019年3月22日周五 下午3:56写道： > > > > > > > > > > Hi Jun, > > > > > > > > > > On Fri, 22 Mar 2019 at 15:20, Jun Nie <jun....@linaro.org> > > > > > wrote: > > > > > > > > > > > > add skipping init option to avoid corrupt data in console > > > > > > if serial is already initilized when u-boot start its excution. > > > > > > > > > > > > Signed-off-by: Jun Nie <jun....@linaro.org> > > > > > > --- > > > > > > drivers/serial/Kconfig | 6 ++++++ > > > > > > 1 file changed, 6 insertions(+) > > > > > > > > > > Could we use a device-tree property for this? Some UARTs have a > > > > > 'skip-init' property. > > > > > > > > > > Regards, > > > > > Simon > > > > > > > > Hi Simon, > > > > > > > > It is a good suggestion. But device tree is board specific, while > > > > the config is boot flow specific. For ATF -> OPTEE -> U-BOOT case, > > > > initialization should be skipped. Without earlier initialization > > > > from firmware, U-boot should do it by itself. So I need find a > > > > solution that is defconfig specific, instead of device tree > > > > specific. > > > > > > So you want something that is flow-specific, I think. Your thinking is > > > that the defconfig specifies this. Is that because certain boards > > > require ATF/Optee? > > > > > > Should we consider having a way to tell U-Boot that it is running > > > from Optee? > > > > > > Could the UART driver detect that the UART is already inited? > > > > Isn't this issue similar to: > > http://patchwork.ozlabs.org/patch/820824/ > > > > and > > > > http://patchwork.ozlabs.org/patch/865963/ > > > My case is that console does not emit any log when OPTEE runs into u-boot. > I already root caused that there is a bug in uart clock handling. > UART1_CLK_ROOT > is hard coded in imx_get_uartclk() of arch/arm/mach-imx/mx7/clock.c > If the console serial is not UART1, 0 may be returned and console does not > work. > > But when I add an IMX_UART_PORT config option in Kconfig to dynamic configure > the CLK_ROOT ID as below, the expansion result is > UARTCONFIG_IMX_UART_PORT_CLK_ROOT instead of UART1_CLK_ROOT. > It seems macro expansion happens before the inclusion of defconfig. Do you see > any better idea other than add the definition in > include/configs/pico-imx7d.h directly? > > #define IMX_UART_CLK_ROOT UART##CONFIG_IMX_UART_PORT##_CLK_ROOT > > Current plan is to add below change so that platform can define > different clock root other > than UART1_CLK_ROOT. > > +++ b/arch/arm/mach-imx/mx7/clock.c > @@ -51,9 +51,12 @@ static u32 get_ipg_clk(void) > return get_ahb_clk() / 2; > } > > +#ifndef UART_CLK_ROOT > +#define UART_CLK_ROOT UART1_CLK_ROOT > +#endif > u32 imx_get_uartclk(void) > { > - return get_root_clk(UART1_CLK_ROOT); > + return get_root_clk(UART_CLK_ROOT); > } >
I'm not very knowledgeable on this platform. This seems OK to me but you should send a patch for iMX people to review. Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
