From: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxxxxxxxxxx>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit c2078d9ef600bdbe568c89e5ddc2c6f15b7982c8 ]
This reverts commit 89a51df5ab1d38b257300b8ac940bbac3bb0eb9b.
The function eeh_add_device_early() is used to perform EEH
initialization in devices added later on the system, like in
hotplug/DLPAR scenarios. Since the commit 89a51df5ab1d ("powerpc/eeh:
Fix crash in eeh_add_device_early() on Cell") a new check was introduced
in this function - Cell has no EEH capabilities which led to kernel oops
if hotplug was performed, so checking for eeh_enabled() was introduced
to avoid the issue.
However, in architectures that EEH is present like pSeries or PowerNV,
we might reach a case in which no PCI devices are present on boot time
and so EEH is not initialized. Then, if a device is added via DLPAR for
example, eeh_add_device_early() fails because eeh_enabled() is false,
and EEH end up not being enabled at all.
This reverts the aforementioned patch since a new verification was
introduced by the commit d91dafc02f42 ("powerpc/eeh: Delay probing EEH
device during hotplug") and so the original Cell issue does not happen
anymore.
Cc: stable@xxxxxxxxxxxxxxx # v4.1+
Reviewed-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
arch/powerpc/kernel/eeh.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index cb565ad..9a4e712 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -1073,7 +1073,7 @@ void eeh_add_device_early(struct pci_dn *pdn)
struct pci_controller *phb;
struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
- if (!edev || !eeh_enabled())
+ if (!edev)
return;
if (!eeh_has_flag(EEH_PROBE_MODE_DEVTREE))
--
2.5.0
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