From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754150AbdLGR7V (ORCPT ); Thu, 7 Dec 2017 12:59:21 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:60687 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755872AbdLGPsm (ORCPT ); Thu, 7 Dec 2017 10:48:42 -0500 From: alexander.levin@verizon.com Cc: Egil Hjelmeland , "David S . Miller" , alexander.levin@verizon.com X-Host: mariner.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.14 080/135] net: dsa: lan9303: Do not disable switch fabric port 0 at .probe Thread-Topic: [PATCH AUTOSEL for 4.14 080/135] net: dsa: lan9303: Do not disable switch fabric port 0 at .probe Thread-Index: AQHTb3J0tphNb3d0nUyZXX/sR/l/tA== Date: Thu, 7 Dec 2017 15:45:49 +0000 Message-ID: <20171207154513.4154-80-alexander.levin@verizon.com> References: <20171207154513.4154-1-alexander.levin@verizon.com> In-Reply-To: <20171207154513.4154-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vB7HxOZm010853 From: Egil Hjelmeland [ Upstream commit 3c91b0c1de8d013490bbc41ce9ee8810ea5baddd ] Make the LAN9303 work when lan9303_probe() is called twice. For some unknown reason the LAN9303 switch fail to forward data when switch fabric port 0 TX is disabled during probe. (Write of LAN9303_MAC_TX_CFG_0 in lan9303_disable_processing_port().) In that situation the switch fabric seem to receive frames, because the ALR is learning addresses. But no frames are transmitted on any of the ports. In our system lan9303_probe() is called twice, first time dsa_register_switch() return -EPROBE_DEFER. As an experiment, modified the code to skip writing LAN9303_MAC_TX_CFG_0, port 0 during the first probe. Then the switch works as expected. Resolve the problem by not calling lan9303_disable_processing_port() on port 0 during probe. Ports 1 and 2 are still disabled. Although unsatisfying that the exact failure mechanism is not known, the patch should not cause any harm. Signed-off-by: Egil Hjelmeland Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/dsa/lan9303-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c index b471413d3df9..1e5a69b9d90a 100644 --- a/drivers/net/dsa/lan9303-core.c +++ b/drivers/net/dsa/lan9303-core.c @@ -569,7 +569,7 @@ static int lan9303_disable_processing(struct lan9303 *chip) { int p; - for (p = 0; p < LAN9303_NUM_PORTS; p++) { + for (p = 1; p < LAN9303_NUM_PORTS; p++) { int ret = lan9303_disable_processing_port(chip, p); if (ret) -- 2.11.0