[U-Boot] [PATCH] pci: restore initialization for DM_PCI

Simon Glass
2016-01-22T03:36:22Z

Hi,

On 21 January 2016 at 18:39, Bin Meng <bmeng.cn@gmail.com> wrote:
> Hi Stephen,
>
> On Fri, Jan 22, 2016 at 7:35 AM, Stephen Warren <swarren@wwwdotorg.org> wrote:
>> From: Stephen Warren <swarren@nvidia.com>
>>
>> PCI controllers should be enumerated at startup so that PCI devices
>> such as Ethernet controllers are available at startup. Fix board_init_r()
>> not to skip calling pci_init() when CONFIG_DM_PCI is defined, and provide
>> an implementation of pci_init() for the DM case.
>>
>
> What exact issue are you trying to fix? I posted the same question on
> Simon's patch [1] before. Does your patch and Simon's fix the same
> issue?
>
> Note I submitted a similar patch [2] last year for x86 only, to
> explicitly trigger the PCI enueration. But it was not accepted.
>
>> Fixes: 96350f729c42 ("dm: tegra: net: Convert tegra boards to driver model
>> for Ethernet")
>> Signed-off-by: Stephen Warren <swarren@nvidia.com>
>> ---
>> I'm not sure if relying on the side-effects of calling
>> uclass_{first,ext}_device is the correct approach; is there a more explicit
>> way to probe all PCI controllers?
>>
>> Arguably, perhaps we should introduce a "pci start" command instead of
>> this change to be consistent with e.g. USB. However, that would be a
>> regression relative to earlier versions of U-Boot.
>> ---
>
> [1] http://patchwork.ozlabs.org/patch/569323/
> [2] http://patchwork.ozlabs.org/patch/500246/
>
> Regards,
> Bin

This does go against the driver-model philosophy of lazy init. I
wonder if we should add this patch with a Kconfig option to enable it?
Then it can be enabled only for boards that need it.

Regards
Simon