From patchwork Tue Nov 23 14:34:21 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Ogness X-Patchwork-Id: 72670 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 51EFAB70D5 for ; Wed, 24 Nov 2010 01:34:43 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754621Ab0KWOed (ORCPT ); Tue, 23 Nov 2010 09:34:33 -0500 Received: from www.tglx.de ([62.245.132.106]:50475 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754507Ab0KWOec (ORCPT ); Tue, 23 Nov 2010 09:34:32 -0500 Received: from merkur.tec.linutronix.de (www.tglx.de [127.0.0.1]) by www.tglx.de (8.13.8/8.13.8/TGLX-2007100201) with ESMTP id oANEYOm7020354; Tue, 23 Nov 2010 15:34:24 +0100 From: John Ogness To: Wolfgang Grandegger Cc: socketcan-core@lists.berlios.de Cc: netdev@vger.kernel.org Cc: kernel@pengutronix.de Subject: [PATCH] flexcan: fix NAPI for bus errors Date: Tue, 23 Nov 2010 15:34:21 +0100 Message-ID: <80k4k45csy.fsf@merkur.tec.linutronix.de> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.95.3 at www.tglx.de X-Virus-Status: Clean X-Spam-Status: No, score=-1.4 required=5.0 tests=ALL_TRUSTED autolearn=failed version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on www.tglx.de Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If bus error reporting is disabled and bus errors occur, the flexcan driver will hog the system because it continually re-enables the IRQs (work_done = 0). This patch changes the driver to only re-enable the IRQs if some work was actually done. This allows the features of NAPI to be used for bus errors as well (when bus error reporting is disabled). This patch is against Linux next-20101123. Signed-off-by: John Ogness --- drivers/net/can/flexcan.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- next-20101123-a/drivers/net/can/flexcan.c +++ next-20101123-b/drivers/net/can/flexcan.c @@ -535,9 +535,12 @@ static int flexcan_poll(struct napi_stru if (work_done < quota) { napi_complete(napi); - /* enable IRQs */ - writel(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); - writel(priv->reg_ctrl_default, ®s->ctrl); + + if (work_done > 0) { + /* enable IRQs */ + writel(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); + writel(priv->reg_ctrl_default, ®s->ctrl); + } } return work_done;