From mboxrd@z Thu Jan 1 00:00:00 1970 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 D6C7CC433F5 for ; Mon, 23 May 2022 17:13:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240004AbiEWRNR (ORCPT ); Mon, 23 May 2022 13:13:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239976AbiEWRLa (ORCPT ); Mon, 23 May 2022 13:11:30 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3464D6CF60; Mon, 23 May 2022 10:10:48 -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 ams.source.kernel.org (Postfix) with ESMTPS id 71346B811FE; Mon, 23 May 2022 17:10:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB92CC385A9; Mon, 23 May 2022 17:10:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653325819; bh=fiL5xmpicU4Z0vpo7J3ojLYAW+ShfyLlGTLoQTbPdiA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PQLxisfMlDNRftlifSr1yj+6J7OwfqpvnfsR+HKDhJjtHWcMi4pPIKfLWbo7Mbyot 96ELnJwND1/4XH4vWvoXUyKLzP5sOokbnZzMi98fnnnIoCtUDY6WLWGjJm7btPB5te G3//p/AlOT2tzd7ptOapRoZeyNpkr0QbvUgBfmfo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Harini Katakam , Michal Simek , Radhey Shyam Pandey , Claudiu Beznea , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 21/44] net: macb: Increment rx bd head after allocating skb and buffer Date: Mon, 23 May 2022 19:05:05 +0200 Message-Id: <20220523165757.014597115@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220523165752.797318097@linuxfoundation.org> References: <20220523165752.797318097@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Harini Katakam [ Upstream commit 9500acc631dbb8b73166e25700e656b11f6007b6 ] In gem_rx_refill rx_prepared_head is incremented at the beginning of the while loop preparing the skb and data buffers. If the skb or data buffer allocation fails, this BD will be unusable BDs until the head loops back to the same BD (and obviously buffer allocation succeeds). In the unlikely event that there's a string of allocation failures, there will be an equal number of unusable BDs and an inconsistent RX BD chain. Hence increment the head at the end of the while loop to be clean. Fixes: 4df95131ea80 ("net/macb: change RX path for GEM") Signed-off-by: Harini Katakam Signed-off-by: Michal Simek Signed-off-by: Radhey Shyam Pandey Reviewed-by: Claudiu Beznea Link: https://lore.kernel.org/r/20220512171900.32593-1-harini.katakam@xilinx.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/cadence/macb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index d8e4842af055..50331b202f73 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -915,7 +915,6 @@ static void gem_rx_refill(struct macb_queue *queue) /* Make hw descriptor updates visible to CPU */ rmb(); - queue->rx_prepared_head++; desc = macb_rx_desc(queue, entry); if (!queue->rx_skbuff[entry]) { @@ -954,6 +953,7 @@ static void gem_rx_refill(struct macb_queue *queue) dma_wmb(); desc->addr &= ~MACB_BIT(RX_USED); } + queue->rx_prepared_head++; } /* Make descriptor updates visible to hardware */ -- 2.35.1