4.8-stable review patch. If anyone has any objections, please let me know.
------------------ From: Andrew Donnellan <[email protected]> commit 409bf7f8a02ef88db5a0f2cdcf9489914f4b8508 upstream. In eeh_reset_device(), we take the pci_rescan_remove_lock immediately after after we call eeh_reset_pe() to reset the PCI controller. We then call eeh_clear_pe_frozen_state(), which can return an error. In this case, we bail out of eeh_reset_device() without calling pci_unlock_rescan_remove(). Add a call to pci_unlock_rescan_remove() in the eeh_clear_pe_frozen_state() error path so that we don't cause a deadlock later on. Reported-by: Pradipta Ghosh <[email protected]> Fixes: 78954700631f ("powerpc/eeh: Avoid I/O access during PE reset") Signed-off-by: Andrew Donnellan <[email protected]> Acked-by: Russell Currey <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/powerpc/kernel/eeh_driver.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -671,8 +671,10 @@ static int eeh_reset_device(struct eeh_p /* Clear frozen state */ rc = eeh_clear_pe_frozen_state(pe, false); - if (rc) + if (rc) { + pci_unlock_rescan_remove(); return rc; + } /* Give the system 5 seconds to finish running the user-space * hotplug shutdown scripts, e.g. ifdown for ethernet. Yes,
