[U-Boot] [PATCH 1/3] arm64: mvebu: Trigger PCI devices scan at early init stage

[Simon Glass]

Hi Konstanitin,

On 30 March 2017 at 07:58, Konstantin Porotchkin <kostap at marvell.com> wrote:
>
>
> On 03/30/2017 04:31 PM, Stefan Roese wrote:
>>
>> (adding Simon to Cc for PCI related question)
>>
>> On 28.03.2017 17:36, kostap at marvell.com wrote:
>>>
>>> From: Konstantin Porotchkin <kostap at marvell.com>
>>>
>>> Add PCIe initialization at early init stage.
>>> This operation has a side effect of detecting all PCIe
>>> plug-in cards, so the operator is not obligated to issue
>>> "pci enum" command though CLI for this purpose.
>>
>>
>> I'm not sure, if this should be handled this way. Simon, how
>> is such a default PCI scan with DM supposed to get done? Is
>> there a way do do this automatically without the need that
>> the user has to issue "pci enum" manually?
>
> I was not sure either, but did not see any other way of doing so.
> I asked to add this change by our Robot/Jenkins automation test team.

It seems reasonable. We actually have some platforms that require PCI
buses to be probed before we know what devices are in the system, and
some of these are important.

For example, if your network controller is on PCI then U-Boot will not
know about it (unless you have it in the device tree) until PCI is
probed.

I am wondering whether we should add a uclass flag that indicates that
uclass members should be automatically probed on start-up?

It would not be set for SATA, but would be for PCI.

>>
>>
>>> Also convert the SATA first device scan to a walk through
>>> all availabel SATA devices.
>>
>>
>> This should be done in a separate patch. But seeing this,
>> won't this SATA / AHCI code be gone completely from this
>> file, once this is converted into a "real" DM AHCI / SCSI
>> driver (please look at my preliminary patch for this).
>
> Will check your patch, thank you.
> Maybe this change has to be completely removed if Simon guide me to the
> right solution for automatic PCIe enumeration.
>

Regards,
Simon