linux-kernel - [PATCH AUTOSEL 4.9 38/43] s390/qeth: reset layer2 attribute on layer switch

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Date:   Fri, 7 Sep 2018 00:38:45 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "stable@...r.kernel.org" <stable@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Julian Wiedmann <jwi@...ux.ibm.com>,
        "David S . Miller" <davem@...emloft.net>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL 4.9 38/43] s390/qeth: reset layer2 attribute on layer
 switch

From: Julian Wiedmann <jwi@...ux.ibm.com>

[ Upstream commit 70551dc46ffa3555a0b5f3545b0cd87ab67fd002 ]

After the subdriver's remove() routine has completed, the card's layer
mode is undetermined again. Reflect this in the layer2 field.

If qeth_dev_layer2_store() hits an error after remove() was called, the
card _always_ requires a setup(), even if the previous layer mode is
requested again.
But qeth_dev_layer2_store() bails out early if the requested layer mode
still matches the current one. So unless we reset the layer2 field,
re-probing the card back to its previous mode is currently not possible.

Signed-off-by: Julian Wiedmann <jwi@...ux.ibm.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
---
 drivers/s390/net/qeth_core_sys.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/s390/net/qeth_core_sys.c b/drivers/s390/net/qeth_core_sys.c
index db6a285d41e0..0a7a6da36dfd 100644
--- a/drivers/s390/net/qeth_core_sys.c
+++ b/drivers/s390/net/qeth_core_sys.c
@@ -423,6 +423,7 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
 	if (card->discipline) {
 		card->discipline->remove(card->gdev);
 		qeth_core_free_discipline(card);
+		card->options.layer2 = -1;
 	}
 
 	rc = qeth_core_load_discipline(card, newdis);
-- 
2.17.1