[PATCH] powerpc/eeh: Fix partial hotplug criterion

[PATCH] powerpc/eeh: Fix partial hotplug criterion

[Gavin Shan]

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")
Cc: stable@vger.kernel.org #v4.4+
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/eeh_driver.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 301be31..650cfb3 100644
--- 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, void *userdata)
 		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;
 	}
 
-- 
2.1.0

Re: powerpc/eeh: Fix partial hotplug criterion

[Michael Ellerman]

On Fri, 2016-12-02 at 05:03:05 UTC, Gavin Shan wrote:
> 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")
> Cc: stable@vger.kernel.org #v4.4+
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/f6bf0fa14cf848ae770e0b7842

cheers