[PATCH 4.4 305/342] powerpc/eeh: Fix partial hotplug criterion

From: Greg Kroah-Hartman
Date: Tue Mar 01 2016 - 19:13:34 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>

commit f6bf0fa14cf848ae770e0b7842c9b11ce2f01645 upstream.

During error recovery, the device could be removed as part of the
partial hotplug. The criterion used to come with partial hotplug
is: if the device driver provides error_detected(), slot_reset()
and resume() callbacks, it's immune from hotplug. Otherwise,
it's going to experience partial hotplug during EEH recovery. But
the criterion isn't correct enough: mlx4_core driver for Mellanox
adapters provides error_detected(), slot_reset() callbacks, but
resume() isn't there. Those Mellanox adapters won't be to involved
in the partial hotplug.

This fixes the criterion to a practical one: adpater with driver
that provides error_detected(), slot_reset() will be immune from
partial hotplug. resume() isn't mandatory.

Fixes: f2da4ccf ("powerpc/eeh: More relaxed hotplug criterion")
Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/kernel/eeh_driver.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -418,8 +418,7 @@ static void *eeh_rmv_device(void *data,
eeh_pcid_put(dev);
if (driver->err_handler &&
driver->err_handler->error_detected &&
- driver->err_handler->slot_reset &&
- driver->err_handler->resume)
+ driver->err_handler->slot_reset)
return NULL;
}