Re: [PATCH v5] driver core: enforce device_lock for driver_match_device()

[Mark Brown]

On Tue, Jan 20, 2026 at 04:03:03PM +0100, Danilo Krummrich wrote:
> On Tue Jan 20, 2026 at 2:22 PM CET, Mark Brown wrote:

> > I'm seeing boot hangs on Arm Juno in next/pending-fixes which bisect to
> > this commit.  The boot grinds to a halt near the end of boot:

> Hm..sounds a bit like some match() callback manually takes the device_lock() and
> the reason we're not seeing anything from lockdep is because it happens with the
> serial driver.

> I don't have a machine to reproduce it, but for debugging it would probably help
> to not actually take the lock in __driver_attach(), but only acquire / release
> the corresponding lockdep map. If my suspicion is correct, we should see a
> lockdep splat pointing out the issue.

lockdep isn't enabled by any of the defconfigs so has limited test
coverage, the only one I'm seeing it enabled by is ps3_defconfig.  I'll
try to run some tests with lockdep enabled.

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