Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934457AbbBCXu4 (ORCPT ); Tue, 3 Feb 2015 18:50:56 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:54993 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754614AbbBCXPU (ORCPT ); Tue, 3 Feb 2015 18:15:20 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Ahmed S. Darwish" , Marc Kleine-Budde Subject: [PATCH 3.18 17/57] can: kvaser_usb: Fix state handling upon BUS_ERROR events Date: Tue, 3 Feb 2015 15:14:08 -0800 Message-Id: <20150203231214.392852551@linuxfoundation.org> X-Mailer: git-send-email 2.2.2 In-Reply-To: <20150203231211.486950145@linuxfoundation.org> References: <20150203231211.486950145@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2055 Lines: 59 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Ahmed S. Darwish" commit e638642b08c170d2021b706f0b1c4f4ae93d8cbd upstream. 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 Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/usb/kvaser_usb.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- 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 st } 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 st 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/