Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 01/16] powerpc/eeh: Fix deadlock when PE frozen state cant be cleared | Date | Tue, 13 Dec 2016 09:15:47 -0800 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
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 <pradghos@in.ibm.com> Fixes: 78954700631f ("powerpc/eeh: Avoid I/O access during PE reset") Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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 @@ -612,8 +612,10 @@ 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,
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