From patchwork Tue Jan 27 08:01:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 433266 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D8AC2140213 for ; Tue, 27 Jan 2015 19:01:43 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757672AbbA0IBj (ORCPT ); Tue, 27 Jan 2015 03:01:39 -0500 Received: from metis.ext.pengutronix.de ([92.198.50.35]:58347 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757214AbbA0IBe (ORCPT ); Tue, 27 Jan 2015 03:01:34 -0500 Received: from gallifrey.ext.pengutronix.de ([2001:6f8:1178:4:5054:ff:fe8d:eefb] helo=hardanger.do.blackshift.org) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1YG15Z-0002Mc-GN; Tue, 27 Jan 2015 09:01:33 +0100 From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, "Ahmed S. Darwish" , linux-stable , Marc Kleine-Budde Subject: [PATCH 4/4] can: kvaser_usb: Fix state handling upon BUS_ERROR events Date: Tue, 27 Jan 2015 09:01:27 +0100 Message-Id: <1422345687-12839-5-git-send-email-mkl@pengutronix.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1422345687-12839-1-git-send-email-mkl@pengutronix.de> References: <1422345687-12839-1-git-send-email-mkl@pengutronix.de> X-SA-Exim-Connect-IP: 2001:6f8:1178:4:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: "Ahmed S. Darwish" While being in an ERROR_WARNING state, and receiving further bus error events with error counters still in the ERROR_WARNING range of 97-127 inclusive, the state handling code erroneously reverts back to ERROR_ACTIVE. Per the CAN standard, only revert to ERROR_ACTIVE when the error counters are less than 96. Moreover, in certain Kvaser models, the BUS_ERROR flag is always set along with undefined bits in the M16C status register. Thus use bitwise operators instead of full equality for checking that register against bus errors. Signed-off-by: Ahmed S. Darwish Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/kvaser_usb.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c index 55407b9663a6..7af379ca861b 100644 --- a/drivers/net/can/usb/kvaser_usb.c +++ b/drivers/net/can/usb/kvaser_usb.c @@ -698,9 +698,7 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev, } new_state = CAN_STATE_ERROR_PASSIVE; - } - - if (status == M16C_STATE_BUS_ERROR) { + } else if (status & M16C_STATE_BUS_ERROR) { if ((priv->can.state < CAN_STATE_ERROR_WARNING) && ((txerr >= 96) || (rxerr >= 96))) { cf->can_id |= CAN_ERR_CRTL; @@ -710,7 +708,8 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev, priv->can.can_stats.error_warning++; new_state = CAN_STATE_ERROR_WARNING; - } else if (priv->can.state > CAN_STATE_ERROR_ACTIVE) { + } else if ((priv->can.state > CAN_STATE_ERROR_ACTIVE) && + ((txerr < 96) && (rxerr < 96))) { cf->can_id |= CAN_ERR_PROT; cf->data[2] = CAN_ERR_PROT_ACTIVE;