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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 2774DC282C4 for ; Mon, 4 Feb 2019 07:23:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8269217D9 for ; Mon, 4 Feb 2019 07:23:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549265006; bh=HDgwpkhTpoTEVDPKrkmykrNSqq9yCCJYhstkDTGaZWE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=SXyeQ2bn1fr029YR6jy7LZFpEfg8Vl2edN9w350blrH5HKKnbvAZ+41deu2yl9mGi rBReGDBwknGHopTh+/ILtvESQjwG69cQDS6gWRBgnbEzRRAOO+w001MEBkveyeXP4o oNrJD+TrpucX1v/0xd8XRrWeqgTFYDcYfmlYOE3Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728076AbfBDHXX (ORCPT ); Mon, 4 Feb 2019 02:23:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:49500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725854AbfBDHXX (ORCPT ); Mon, 4 Feb 2019 02:23:23 -0500 Received: from localhost (unknown [171.76.74.253]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 92B4A2083B; Mon, 4 Feb 2019 07:23:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549265002; bh=HDgwpkhTpoTEVDPKrkmykrNSqq9yCCJYhstkDTGaZWE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nUKyNq6Hts9oKpqFVbZ/mpkxPAtFK43ibh8WLBgzpsTvo7+BLeLG5N0+7brbVEffc WQAhP+A6rr5jgbzfuyTzgN6G6JdhQPfOglnHO9KqhfXhN3TKwqUlBNTOueG8khTv9Z Lrpbh+ZuDSqochHp+jcQVvER3BRaDmXY7Yb8fB4Q= Date: Mon, 4 Feb 2019 12:51:54 +0530 From: Vinod Koul To: Long Cheng Cc: Randy Dunlap , Rob Herring , Mark Rutland , Ryder Lee , Sean Wang , Nicolas Boichat , Matthias Brugger , Dan Williams , Greg Kroah-Hartman , Jiri Slaby , Sean Wang , dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, srv_heupstream@mediatek.com, Yingjoe Chen , YT Shen , Zhenbao Liu Subject: Re: [PATCH v10 1/3] dmaengine: 8250_mtk_dma: add MediaTek uart DMA support Message-ID: <20190204072154.GJ4296@vkoul-mobl> References: <1547781016-890-1-git-send-email-long.cheng@mediatek.com> <1547781016-890-2-git-send-email-long.cheng@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1547781016-890-2-git-send-email-long.cheng@mediatek.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18-01-19, 11:10, Long Cheng wrote: > +static enum dma_status mtk_uart_apdma_tx_status(struct dma_chan *chan, > + dma_cookie_t cookie, > + struct dma_tx_state *txstate) > +{ > + struct mtk_chan *c = to_mtk_uart_apdma_chan(chan); > + enum dma_status ret; > + unsigned long flags; > + > + if (!txstate) > + return DMA_ERROR; Why, it is not a mandatory arg! > + ret = dma_cookie_status(chan, cookie, txstate); > + spin_lock_irqsave(&c->vc.lock, flags); > + if (ret == DMA_IN_PROGRESS) { > + c->rx_status = mtk_uart_apdma_read(c, VFF_RPT) & VFF_RING_SIZE; > + dma_set_residue(txstate, c->rx_status); > + } else if (ret == DMA_COMPLETE && c->dir == DMA_DEV_TO_MEM) { > + dma_set_residue(txstate, c->rx_status); what is the point is setting residue to comleted txn, it is zero! > + } else { > + dma_set_residue(txstate, 0); naah that doesnt sound correct! > +static void mtk_uart_apdma_config_write(struct dma_chan *chan, > + struct dma_slave_config *cfg, > + enum dma_transfer_direction dir) > +{ > + struct mtk_chan *c = to_mtk_uart_apdma_chan(chan); > + struct mtk_uart_apdmadev *mtkd = > + to_mtk_uart_apdma_dev(c->vc.chan.device); > + unsigned int tmp; > + > + if (mtk_uart_apdma_read(c, VFF_EN) == VFF_EN_B) > + return; > + > + c->dir = dir; > + > + if (dir == DMA_DEV_TO_MEM) { > + tmp = cfg->src_addr_width * 1024; why multiply by 1024? > +static int mtk_uart_apdma_device_pause(struct dma_chan *chan) > +{ > + /* just for check caps pass */ > + return 0; > +} please remove, this is not a mandatory fn -- ~Vinod