From patchwork Fri May 13 14:23:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 572544 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88177C433F5 for ; Fri, 13 May 2022 14:24:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357422AbiEMOYo (ORCPT ); Fri, 13 May 2022 10:24:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358971AbiEMOYm (ORCPT ); Fri, 13 May 2022 10:24:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EE995E168; Fri, 13 May 2022 07:24:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7CA4D62153; Fri, 13 May 2022 14:24:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E621C34100; Fri, 13 May 2022 14:24:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652451872; bh=QF88le2UwZdYFdKhakOikXNGtWetoJ79BBE9pUZFl9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e6iB7bEktaQM5DqEAPMQ3Ex63pBzsKL5IDrHLYwj32tJU1MlW1RTdIZCNkpGbZm74 GtRBEYOm31C5wdQxAAky+tOFYF4tlHCf4SmCtqJzXP3QdJCekXkwvWdOHEHuYL5LAR r1K2RqWt32UePPcGl/JH3j9hN6WU+WzBpxRC/pY8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andreas Larsson , Marc Kleine-Budde Subject: [PATCH 4.9 4/7] can: grcan: only use the NAPI poll budget for RX Date: Fri, 13 May 2022 16:23:19 +0200 Message-Id: <20220513142226.041910821@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220513142225.909697091@linuxfoundation.org> References: <20220513142225.909697091@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andreas Larsson commit 2873d4d52f7c52d60b316ba6c47bd7122b5a9861 upstream. The previous split budget between TX and RX made it return not using the entire budget but at the same time not having calling called napi_complete. This sometimes led to the poll to not be called, and at the same time having TX and RX interrupts disabled resulting in the driver getting stuck. Fixes: 6cec9b07fe6a ("can: grcan: Add device driver for GRCAN and GRHCAN cores") Link: https://lore.kernel.org/all/20220429084656.29788-4-andreas@gaisler.com Cc: stable@vger.kernel.org Signed-off-by: Andreas Larsson Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/grcan.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) --- a/drivers/net/can/grcan.c +++ b/drivers/net/can/grcan.c @@ -1141,7 +1141,7 @@ static int grcan_close(struct net_device return 0; } -static int grcan_transmit_catch_up(struct net_device *dev, int budget) +static void grcan_transmit_catch_up(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); unsigned long flags; @@ -1149,7 +1149,7 @@ static int grcan_transmit_catch_up(struc spin_lock_irqsave(&priv->lock, flags); - work_done = catch_up_echo_skb(dev, budget, true); + work_done = catch_up_echo_skb(dev, -1, true); if (work_done) { if (!priv->resetting && !priv->closing && !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) @@ -1163,8 +1163,6 @@ static int grcan_transmit_catch_up(struc } spin_unlock_irqrestore(&priv->lock, flags); - - return work_done; } static int grcan_receive(struct net_device *dev, int budget) @@ -1246,19 +1244,13 @@ static int grcan_poll(struct napi_struct struct net_device *dev = priv->dev; struct grcan_registers __iomem *regs = priv->regs; unsigned long flags; - int tx_work_done, rx_work_done; - int rx_budget = budget / 2; - int tx_budget = budget - rx_budget; + int work_done; - /* Half of the budget for receiveing messages */ - rx_work_done = grcan_receive(dev, rx_budget); + work_done = grcan_receive(dev, budget); - /* Half of the budget for transmitting messages as that can trigger echo - * frames being received - */ - tx_work_done = grcan_transmit_catch_up(dev, tx_budget); + grcan_transmit_catch_up(dev); - if (rx_work_done < rx_budget && tx_work_done < tx_budget) { + if (work_done < budget) { napi_complete(napi); /* Guarantee no interference with a running reset that otherwise @@ -1275,7 +1267,7 @@ static int grcan_poll(struct napi_struct spin_unlock_irqrestore(&priv->lock, flags); } - return rx_work_done + tx_work_done; + return work_done; } /* Work tx bug by waiting while for the risky situation to clear. If that fails,