Re: [PATCH] PCI: rockchip-host: Enable async probe by default

[Bjorn Helgaas <helgaas@kernel.org>]

On Mon, Nov 09, 2026 at 10:47:39PM +0200, Igor Velkov wrote:
> On Mon, Nov 09, 2026 at 02:22:02PM -0600, Bjorn Helgaas wrote:
> > I don't know what the SD card has to do with PCIe.  Seems like there's
> > some SD issue, and making PCIe async happens to avoid it?  Sounds
> > fragile to me.
> >
> > Other changes like c0e1eb441b1d justify it by allowing other drivers
> > to load in parallel to reduce boot time, which is a good reason.  But
> > apparently here it makes a functional difference as well, which feels
> > sketchy.  E.g., what other drivers need to use async probe to avoid
> > similar issues?
> 
> You're right that the real problem is ordering: nothing makes dw_mmc wait
> for the RK3399 io-domain driver, which sets the 1.8 V level of the SD
> pins. [1] tried to add that dependency and was not merged. Async probe
> only stops this driver from holding the deferred-probe worker for ~0.7 s;
> any other slow probe in that window breaks UHS the same way.
> 
> Is there a way to express this dependency that you would accept?
> 
> [1] https://lore.kernel.org/all/20230904115816.1237684-1-s.hauer@pengutronix.de/

Mani's already applied it, so I think it's fine.  I'm just trying to
understand the commit message and figure out what the merge commit log
and the eventual pull request should say.  It sounds like "this makes
SD cards work better" is somehow part of it, but it just feels kind of
hand-wavey.