Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Jeroen Hofstee <jhofstee@victronenergy.com>
To:     linux-can@vger.kernel.org
Cc:     jhofstee@victronenergy.com,
        Wolfgang Grandegger <wg@grandegger.com>,
        Marc Kleine-Budde <mkl@pengutronix.de>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] can: ti_hecc: fix close when napi poll is active
Date:   Sat,  7 Apr 2018 22:21:39 +0200
Message-Id: <1523132500-26070-1-git-send-email-jhofstee@victronenergy.com>
MIME-Version: 1.0
Content-Type: text/plain
Received-SPF: None (protection.outlook.com: victronenergy.com does not
 designate permitted sender hosts)
SpamDiagnosticOutput: 1:99
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Apr 2018 20:22:13.4957 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 3f25da56-99f6-4016-9352-08d59cc53fd2
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 60b95f08-3558-4e94-b0f8-d690c498e225
X-MS-Exchange-Transport-CrossTenantHeadersStamped: HE1PR07MB1065
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

When closing this CAN interface while napi poll is active, for example with:
`ip link set can0 down` several interfaces freeze. This seemed to be caused
by napi_disable called from ti_hecc_close expecting the scheduled probe to
either return quota or call napi_complete. Since the poll functions has a
check for netif_running it returns 0 and doesn't call napi_complete and hence
violates the napi its expectation.

So remove this check, so either napi_complete is called or quota is returned.

Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
---
 drivers/net/can/ti_hecc.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c
index db6ea93..42813d3 100644
--- a/drivers/net/can/ti_hecc.c
+++ b/drivers/net/can/ti_hecc.c
@@ -603,9 +603,6 @@ static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
 	u32 mbx_mask;
 	unsigned long pending_pkts, flags;
 
-	if (!netif_running(ndev))
-		return 0;
-
 	while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
 		num_pkts < quota) {
 		mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
-- 
2.7.4