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 X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F34BC48BD6 for ; Wed, 26 Jun 2019 16:33:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F017C205C9 for ; Wed, 26 Jun 2019 16:33:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726531AbfFZQdT (ORCPT ); Wed, 26 Jun 2019 12:33:19 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:37580 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726006AbfFZQdT (ORCPT ); Wed, 26 Jun 2019 12:33:19 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id CB29414B5B882; Wed, 26 Jun 2019 09:33:18 -0700 (PDT) Date: Wed, 26 Jun 2019 09:33:18 -0700 (PDT) Message-Id: <20190626.093318.2241574529231651608.davem@davemloft.net> To: Jose.Abreu@synopsys.com Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Joao.Pinto@synopsys.com, peppe.cavallaro@st.com, alexandre.torgue@st.com Subject: Re: [PATCH net-next 01/10] net: stmmac: dwxgmac: Enable EDMA by default From: David Miller In-Reply-To: <6df599b8c2d57db9d82e42861ce897d7cf003424.1561556555.git.joabreu@synopsys.com> References: <6df599b8c2d57db9d82e42861ce897d7cf003424.1561556555.git.joabreu@synopsys.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 26 Jun 2019 09:33:19 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jose Abreu Date: Wed, 26 Jun 2019 15:47:35 +0200 > @@ -122,6 +122,8 @@ static void dwxgmac2_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi) > } > > writel(value, ioaddr + XGMAC_DMA_SYSBUS_MODE); > + writel(GENMASK(29, 0), ioaddr + XGMAC_TX_EDMA_CTRL); > + writel(GENMASK(29, 0), ioaddr + XGMAC_RX_EDMA_CTRL); > } This mask is magic and there is no indication what the bits mean and in particular what it means to set bits 0 -- 29 You have to document what these bits mean and thus what these register writes actually do.