Re: [PATCH 1/4] PCI: dw-rockchip: Do not enumerate bus before endpoint devices are ready

Bjorn Helgaas
2025-06-12T13:19:41Z

On Thu, Jun 12, 2025 at 01:19:45PM +0200, Niklas Cassel wrote:
> On Wed, Jun 11, 2025 at 04:14:56PM -0500, Bjorn Helgaas wrote:
> > On Wed, Jun 11, 2025 at 12:51:42PM +0200, Niklas Cassel wrote:
> > > Commit ec9fd499b9c6 ("PCI: dw-rockchip: Don't wait for link since we can
> > > detect Link Up") changed so that we no longer call dw_pcie_wait_for_link(),
> > > and instead enumerate the bus directly after receiving the Link Up IRQ.
> > >
> > > This means that there is no longer any delay between link up and the bus
> > > getting enumerated.

> > I think the comment at the PCIE_T_RRS_READY_MS definition should be
> > enough (although it might need to be updated to mention link-up).
> > This delay is going to be a standard piece of every driver, so it
> > won't require special notice.
>
> Looking at pci.h, we already have a comment mentioning exactly this
> (link-up):
> https://github.com/torvalds/linux/blob/v6.16-rc1/drivers/pci/pci.h#L51-L63
>
> I will change the patches to use PCIE_RESET_CONFIG_DEVICE_WAIT_MS instead.

I'll more closely later, but I think PCIE_T_RRS_READY_MS and
PCIE_RESET_CONFIG_DEVICE_WAIT_MS are duplicates and only one should
exist. It looks like they got merged at about the same time by
different people, so we didn't notice.

Bjorn