Re: [PATCH] Revert "PCI: Remove from bus_list and release resourcesin pci_release_dev()"

[Mika Westerberg]

On Sat, Feb 01, 2014 at 03:38:29PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Subject: Revert "PCI: Remove from bus_list and release resources in pci_release_dev()"
> 
> Revert commit ef83b0781a73 "PCI: Remove from bus_list and release
> resources in pci_release_dev()" that made some nasty race conditions
> become possible.  For example, if a Thunderbolt link is unplugged
> and then replugged immediately, the pci_release_dev() resulting from
> the hot-remove code path may be racing with the hot-add code path
> which after that commit causes various kinds of breakage to happen
> (up to and including a hard crash of the whole system).
> 
> Moreover, the problem that commit ef83b0781a73 attempted to address
> cannot happen any more after commit 8a4c5c329de7 "PCI: Check parent
> kobject in pci_destroy_dev()", because pci_destroy_dev() will now
> return immediately if it has already been executed for the given
> device.
> 
> Note, however, that the invocation of msi_remove_pci_irq_vectors()
> removed by commit ef83b0781a73 from pci_free_resources() along with
> the other changes made by it is not added back because of subsequent
> code changes depending on that modification.
> 
> Fixes: ef83b0781a73 (PCI: Remove from bus_list and release resources in pci_release_dev())
> Reported-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Thanks, that fixes the problem I'm seeing.
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