[U-Boot] [PATCH 3/3] x86: fsp: Disable legacy internal UART if necessary

[Stefan Roese]

Hi Bin,

On 19.01.2016 09:40, Bin Meng wrote:
> Hi Stefan,
>
> On Mon, Jan 18, 2016 at 5:56 PM, Stefan Roese <sr at denx.de> wrote:
>> The FSP enables the BayTrail internal UART (again). Boards that don't use
>> this UART but an external one instead (e.g. provided by a Super IO chip)
>> need to disable this internal UART. So that the one from the Super IO
>> chip can be used. This patch adds the necessary code, to disable the
>> internal legacy UART if the Winbond Super IO chip is enabled.
>>
>> Signed-off-by: Stefan Roese <sr at denx.de>
>> Cc: Bin Meng <bmeng.cn at gmail.com>
>> Cc: Simon Glass <sjg at chromium.org>
>> ---
>>   arch/x86/lib/fsp/fsp_support.c | 14 ++++++++++++++
>>   1 file changed, 14 insertions(+)
>>
>> diff --git a/arch/x86/lib/fsp/fsp_support.c b/arch/x86/lib/fsp/fsp_support.c
>> index 875c96a..8114b81 100644
>> --- a/arch/x86/lib/fsp/fsp_support.c
>> +++ b/arch/x86/lib/fsp/fsp_support.c
>> @@ -89,6 +89,13 @@ struct fsp_header *__attribute__((optimize("O0"))) find_fsp_header(void)
>>
>>   void fsp_continue(u32 status, void *hob_list)
>>   {
>> +       /*
>> +        * The FSP enables the BayTrail internal legacy UART (again).
>> +        * Disable it again, so that the Winbond one can be used.
>> +        */
>> +       if (IS_ENABLED(CONFIG_WINBOND_W83627))
>> +               disable_internal_uart();
>> +
>
> I would put this into the board_init_f(), right before enabling super
> I/O legacy UART. This way we avoid changing the generic FSP codes.
>
>>          post_code(POST_MRC);
>>
>>          assert(status == 0);
>> @@ -114,6 +121,13 @@ void fsp_init(u32 stack_top, u32 boot_mode, void *nvs_buf)
>>          setup_early_uart();
>>   #endif
>>
>> +       /*
>> +        * To use the Winbond legacy UART (COM1), the BayTrail internal
>> +        * legacy UART needs to get disabled first.
>> +        */
>> +       if (IS_ENABLED(CONFIG_WINBOND_W83627))
>> +               disable_internal_uart();
>> +
>
> I don't think this change is needed as fsp_init() will enable legacy
> UART anyway.

You are correct. This patch is not needed at all, when I move the
call to disable_internal_uart() to the board specific code.

So I withdraw this patch and will send updated versions of the
other 2 patches.

Thanks,
Stefan