[U-Boot] [U-Boot,v3,09/13] ns16550: unify serial_tegra

[Yegor Yefremov]

On Fri, Dec 4, 2015 at 2:59 PM, Thomas Chou <thomas at wytron.com.tw> wrote:
> Hi Stephen,
>
>
> On 2015年12月04日 06:55, Stephen Warren wrote:
>>
>> The patch below appears to solve the problem. Any ideas how to fix this
>> cleanly? I don't think we want to introduce a CONFIG_SPL_xxx for every
>> CONFIG_xxx, yet CONFIG_IS_ENABLED() (e.g. used around
>> arch/arm/mach-tegra/board.c's U_BOOT_DEVICE(ns16550_com1) definition)
>> seems to require this.
>>
>> Unfortunately, the patch doesn't revert cleanly, or at least would
>> require other more recent patches to be reverted first.
>>
>> Also, while debugging this I found that U-Boot force-probes any device
>> referenced by /chosen/stdout-path even if the DT node is disabled; yet
>> more fundamental incorrect DT processing:-( That's why the patch below
>> only affects SPL. More fixes to actually enable the serial port in DT
>> should be required.
>>
>> diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
>> index fbfb204e6ec8..15609e7dc773 100644
>> --- a/arch/arm/mach-tegra/Kconfig
>> +++ b/arch/arm/mach-tegra/Kconfig
>> @@ -1,5 +1,8 @@
>>   if TEGRA
>>
>> +config SPL_DM_SERIAL
>> +    bool "Fix build"
>> +
>>   config TEGRA_COMMON
>>       bool "Tegra common options"
>>       select DM
>> @@ -12,6 +15,7 @@ config TEGRA_COMMON
>>       select DM_SPI
>>       select DM_SPI_FLASH
>>       select OF_CONTROL
>> +    select SPL_DM_SERIAL
>>
>
> But all serial drivers should be converted to driver model by the end of
> Jan, 2016. The DM_SERIAL should be removed then.
>
> As SPL might not use OF_CONTROL. We might need better logic in tegra board.c
> like,
>   SPL_BUILD ? SPL_OF_CONTROL : OF_CONTROL
>
>
>>   config TEGRA_ARMV7_COMMON
>>       bool "Tegra 32-bit common options"
>> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
>> index 166deabcd436..256c7eafd76e 100644
>> --- a/drivers/serial/ns16550.c
>> +++ b/drivers/serial/ns16550.c
>> @@ -451,5 +451,6 @@ U_BOOT_DRIVER(ns16550_serial) = {
>>       .priv_auto_alloc_size = sizeof(struct NS16550),
>>       .probe = ns16550_serial_probe,
>>       .ops    = &ns16550_serial_ops,
>> +    .flags    = DM_FLAG_PRE_RELOC,
>
>
> Yes, this pre-reloc flag should be added.
>
>>   };
>>   #endif /* CONFIG_DM_SERIAL */

Have the same issue with am335x boards
(http://lists.denx.de/pipermail/u-boot/2015-December/236615.html).

Yegor