[U-Boot] [PATCH] arm: socfpga: make debug uart work on socfpga_gen5

[Simon Goldschmidt]

Am 07.01.2019 um 21:25 schrieb Marek Vasut:
> On 1/7/19 9:24 PM, Simon Goldschmidt wrote:
>> Am 07.01.2019 um 21:19 schrieb Marek Vasut:
>>> On 1/7/19 8:36 PM, Simon Goldschmidt wrote:
>>>> When debug UART is enabled on socfpga_gen5, the debug uart driver hangs
>>>> in an endless loop because 'socfpga_bridges_reset' calls printf before
>>>> the debug UART is initialized.
>>>>
>>>> After the generic fix for this in the UART driver did not work due to
>>>> portability issues, let's just drop this printf statement when called
>>>> from SPL with debug UART enabled.
>>>>
>>>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
>>>
>>> Can we have an un-portable fix which at least works on SoCFPGA ? :)
>>
>> This one worked on socfpga but broke rockchip:
>>
>> https://patchwork.ozlabs.org/patch/992553/
>>
>> However, the message below wasn't shown either with that patch applied.
>> The code just runs too early to enable the UART.
>>
>> Do you want to keep the message (although I failed to see in which
>> situation it can be printed) or do you just dislike the #ifdef thing?
> 
> I'd like to keep the error message if possible. Is it possible ?

I have *never* seen this message yet. I have failed to produce a 
situation where it is shown.

This function ('socfpga_bridges_reset') is called 5 times throughout the 
code, but only *one* single time with 'reset=0' as argument (only with 
0, the code in question is executed). And this is in SPL before 
initializing the console and even before the debug UART can be initialized.

As I could see, the printf *is* executed on every boot (I saw the code 
hanging when enabling debug UART). However, when not booting from FPGA, 
it is just normal that the FPGA is not ready when running SPL. Why do 
you want an error message here anyway?

Regards,
Simon