Re: [GIT PULL] Driver core changes for 6.0-rc1

From: Greg KH <gregkh@linuxfoundation.org>
To: Saravana Kannan <saravanak@google.com>, Olof Johansson <olof@lixom.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Linux ARM Mailing List <linux-arm-kernel@lists.infradead.org>,
	Shawn Guo <shawnguo@kernel.org>, Li Yang <leoyang.li@nxp.com>
Subject: Re: [GIT PULL] Driver core changes for 6.0-rc1
Date: Wed, 14 Sep 2022 16:00:37 +0200	[thread overview]
Message-ID: <YyHehZ5hT8mXKoTX@kroah.com> (raw)
In-Reply-To: <CAOesGMjQHhTUMBGHQcME4JBkZCof2NEQ4gaM1GWFgH40+LN9AQ@mail.gmail.com>

On Tue, Sep 13, 2022 at 09:28:27AM -0700, Olof Johansson wrote:
> On Tue, Sep 13, 2022 at 8:15 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Mon, Sep 12, 2022 at 10:24:43AM -0700, Olof Johansson wrote:
> > > On Mon, Sep 12, 2022 at 10:23 AM Olof Johansson <olof@lixom.net> wrote:
> > > >
> > > > Hi,
> > > >
> > > > On Wed, Aug 3, 2022 at 7:16 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > > Saravana Kannan (11):
> > > > >       PM: domains: Delete usage of driver_deferred_probe_check_state()
> > > > >       pinctrl: devicetree: Delete usage of driver_deferred_probe_check_state()
> > > > >       net: mdio: Delete usage of driver_deferred_probe_check_state()
> > > > >       driver core: Add wait_for_init_devices_probe helper function
> > > > >       net: ipconfig: Relax fw_devlink if we need to mount a network rootfs
> > > > >       Revert "driver core: Set default deferred_probe_timeout back to 0."
> > > > >       driver core: Set fw_devlink.strict=1 by default
> > > > >       iommu/of: Delete usage of driver_deferred_probe_check_state()
> > > > >       driver core: Delete driver_deferred_probe_check_state()
> > > > >       driver core: fw_devlink: Allow firmware to mark devices as best effort
> > > > >       of: base: Avoid console probe delay when fw_devlink.strict=1
> > > >
> > > > The last patch in this list regresses my HoneyComb LX2K (ironically
> > > > the machine I do maintainer work on). It stops PCIe from probing, but
> > > > without a single message indicating why.
> > > >
> > > > The reason seems to be that the iommu-maps property doesn't get
> > > > patched up by my (older) u-boot, and thus isn't a valid reference.
> > > > System works fine without IOMMU, which is how I've ran it for a couple
> > > > of years.
> > > >
> > > > It's also extremely hard to diagnose out of the box because there are
> > > > *no error messages*. And there were no warnings leading up to this
> > > > strict enforcement.
> > > >
> > > > This "feature" seems to have been done backwards. The checks should
> > > > have been running (and not skipped due to the "optional" flag), but
> > > > also not causing errors, just warnings. That would have given users a
> > > > chance to know that this is something that needs to be fixed.
> > > >
> > > > And when you flip the switch, at least report what failed so that
> > > > people don't need to spend a whole night bisecting kernels, please.
> > > >
> > > > Greg, mind reverting just the last one? If I hit this, I presume
> > > > others would too.
> > >
> > > Apologies, wrong patch pointed out. The culprit is "driver core: Set
> > > fw_devlink.strict=1 by default", 71066545b48e42.
> >
> > Is this still an issue in -rc5?  A number of patches in the above series
> > was just reverted and hopefully should have resolved the issue you are
> > seeing.
> 
> Unfortunately, I discovered this regression with -rc5 in the first
> place, so it's still there.

Ick, ok, Saravana, any thoughts?  I know you're at the conference this
week with me, maybe you can give Olof a hint as to what to look for
here?

thanks,

greg k-h