Re: [PATCH v1 0/3] Bring back driver_deferred_probe_check_state() for now

From: Doug Anderson
Date: Tue Aug 09 2022 - 19:47:08 EST


Hi,

On Thu, Jul 28, 2022 at 12:29 AM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Jul 27, 2022 at 11:50:08AM -0700, Saravana Kannan wrote:
> > More fixes/changes are needed before driver_deferred_probe_check_state()
> > can be deleted. So, bring it back for now.
> >
> > Greg,
> >
> > Can we get this into 5.19? If not, it might not be worth picking up this
> > series. I could just do the other/more fixes in time for 5.20.
>
> Wow, no, it is _WAY_ too late for 5.19 to make a change like this,
> sorry.
>
> What is so broken that we need to revert these now? I could do so for
> 5.20-rc1, and then backport to 5.19.y if that release is really broken,
> but this feels odd so late in the cycle.

I spent a bunch of time bisecting mainline today on my
sc7180-trogdor-lazor board. When building the top of Linus's tree
today the display doesn't come up. I can make it come up by turning
fw_devlink off (after fixing a regulator bug that I just posted a fix
for).

I found that the first bad commit was commit 5a46079a9645 ("PM:
domains: Delete usage of driver_deferred_probe_check_state()")

...but only when applied to mainline. When I cherry-pick that back to
v5.19-rc1 (and pick another bugfix needed to boot my board against
v5.19-rc1) then it works OK. After yet more bisecting, I found that on
trogdor there's a bad interaction with the commit e511a760 ("arm64:
dts: qcom: sm7180: remove assigned-clock-rate property for mdp clk").
That commit is perfectly legit but I guess it somehow changed how
fw_devlink was interpreting things?

Sure enough, picking this revert series fixes things on Linus's tree.
Any chance we can still get the revert in for v5.20-rc1? ;-)


-Doug