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

From: Olof Johansson <olof@lixom.net>
To: Greg KH <gregkh@linuxfoundation.org>
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>,
	Saravana Kannan <saravanak@google.com>,
	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: Mon, 12 Sep 2022 10:24:43 -0700	[thread overview]
Message-ID: <CAOesGMgKM9gU9qNEiLb==pE_u-W7HTGd0s75CL38u6Eve2Uchg@mail.gmail.com> (raw)
In-Reply-To: <CAOesGMivEZmYb7Z8C1ic=r0oeNeXBh61LYu28B1g9d_qZVOjyA@mail.gmail.com>

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.

-Olof