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From: Lukas Wunner <lukas@wunner.de>
To: Raju Rangoju <Raju.Rangoju@amd.com>
Cc: bhelgaas@google.com, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, Sanath S <Sanath.S@amd.com>
Subject: Re: [PATCH] PCI: pciehp: fix circular lock dependency b/w pci_rescan_remove_lock and reset_lock
Date: Thu, 19 Jun 2025 18:19:41 +0200	[thread overview]
Message-ID: <aFQ4ncPNdmUgyw63@wunner.de> (raw)
In-Reply-To: <20250619154610.902892-1-Raju.Rangoju@amd.com>

On Thu, Jun 19, 2025 at 09:16:10PM +0530, Raju Rangoju wrote:
> Resolves a circular locking dependency issue between
> pci_rescan_remove_lock() and ctrl->reset_lock() in the PCI hotplug
> subsystem, specifically in the pciehp_unconfigure_device() function.

This seems to be a false-positive because the two stacktraces are identical
but pciehp_ist() is single-threaded.  There is only ever a single instance
of pciehp_ist() running per hotplug port, so two instances running on
separate CPUs can never happen.

Previous reports of the same false-positive lockdep splat, only they
refer to pciehp_configure_device() instead of pciehp_unconfigure_device():

https://lore.kernel.org/r/20231015093722.GA11283@wunner.de/
https://lore.kernel.org/r/ZzJm6QrQyT48jGuN@wunner.de/

Thanks,

Lukas

      reply	other threads:[~2025-06-19 16:19 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-19 15:46 [PATCH] PCI: pciehp: fix circular lock dependency b/w pci_rescan_remove_lock and reset_lock Raju Rangoju
2025-06-19 16:19 ` Lukas Wunner [this message]

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