From patchwork Fri Jun 10 11:28:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Crispin X-Patchwork-Id: 9169507 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A82126048C for ; Fri, 10 Jun 2016 11:28:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A0262835D for ; Fri, 10 Jun 2016 11:28:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8E62428362; Fri, 10 Jun 2016 11:28:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 85D3D28359 for ; Fri, 10 Jun 2016 11:28:55 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bBKcQ-0001EO-9u; Fri, 10 Jun 2016 11:28:54 +0000 Received: from nbd.name ([2a01:4f8:131:30e2::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bBKcO-00019R-G5 for linux-mediatek@lists.infradead.org; Fri, 10 Jun 2016 11:28:53 +0000 From: John Crispin To: "David S. Miller" Subject: [PATCH V2 09/11] net: mediatek: fix off by one in the TX ring allocation Date: Fri, 10 Jun 2016 13:28:06 +0200 Message-Id: <1465558088-15265-10-git-send-email-john@phrozen.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1465558088-15265-1-git-send-email-john@phrozen.org> References: <1465558088-15265-1-git-send-email-john@phrozen.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160610_042852_794464_7518563A X-CRM114-Status: UNSURE ( 8.15 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sean Wang , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, John Crispin , Felix Fietkau MIME-Version: 1.0 Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+patchwork-linux-mediatek=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The TX ring setup has an off by one error causing it to not utilise all descriptors. This has the side effect that we need to reset the next pointer at runtime to make it work. Fix the off by one and remove the code fixing the ring at runtime. Signed-off-by: John Crispin --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index 24714ab..6daf48b 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -903,7 +903,6 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget, bool *tx_again) } mtk_tx_unmap(eth->dev, tx_buf); - ring->last_free->txd2 = next_cpu; ring->last_free = desc; atomic_inc(&ring->free_count); @@ -1011,7 +1010,7 @@ static int mtk_tx_alloc(struct mtk_eth *eth) atomic_set(&ring->free_count, MTK_DMA_SIZE - 2); ring->next_free = &ring->dma[0]; - ring->last_free = &ring->dma[MTK_DMA_SIZE - 2]; + ring->last_free = &ring->dma[MTK_DMA_SIZE - 1]; ring->thresh = MAX_SKB_FRAGS; /* make sure that all changes to the dma ring are flushed before we