[U-Boot] [PATCH 4/4] ARM: socfpga: Add support for selecting bridges in bridge command

[Simon Goldschmidt]

Am 22.04.2019 um 20:01 schrieb Marek Vasut:
> On 4/19/19 10:00 PM, Simon Goldschmidt wrote:
>>
>>
>> On 17.04.19 22:15, Marek Vasut wrote:
>>> Add optional "mask" argument to the SoCFPGA bridge command, to select
>>> which bridges should be enabled/disabled. This allows the user to avoid
>>> enabling bridges which are not connected into the FPGA fabric. Default
>>> behavior is to enable/disable all bridges.
>>
>> So does this change the command? Seems like leaving away the new 'mask'
>> argument would now lead to enabling all bridges by overwriting whatever
>> the handoff values were before?
> 
> That's how it behaved before though -- all the bridges were enabled.
> Now it's possible to explicitly select which bridges to enable/disable.

As I read the code, before it wrote iswgrp_handoff[x] to the registers. 
The question is what is iswgrp_handoff[x]. It's not the bridges status 
from Quartus (as the "handoff" suffix might suggest). Instead (if I 
remember correctly), it's either "all bridges" or "no bridges", 
depending on the FPGA configuration status at SPL runtime.

In this case, we're probably better off with leaving it to the command 
line scripts to say which bridges shall be enabled...

Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>