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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 6A2D5C072B1 for ; Fri, 17 May 2019 07:37:21 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 37D672082E for ; Fri, 17 May 2019 07:37:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="LQUlEMBM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37D672082E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=dqG76dtfpbswfQXUO/HCCEBd1hHCUG+B3qVqUc9MdqE=; b=LQUlEMBMSthk1R tTiryX7brSoTnso5ABwy1ENDyNNoXcBaTTtEKT+AsC9rg2Ow7kQAH4BjW/9b4Mz6a42KxTX18FYky svLYRbYWqNuWxeL7bVGvi+I3DFBwbf3GOCkKVQgeKkQNjuqPlB2VGABJBcJsWZYnLIQxBdP6fQBx2 uz2sqIWGEdDa29rAsEIBH2YeSmU/Q3KdjkW/FxPqefTeFkbYDCpWnBo3AtoJ0lLb7hjS/hU1IkHvJ yT9I0ZtVSBCGPrzBonFi8H1D2PH9/yQ1WQwQsg18IcC9ozXcRJ6oqhEl3hFF52nyg+N8LXFK6kzWD cHWL/esI++7zakQa/vOg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hRXQX-0003JE-3b; Fri, 17 May 2019 07:37:13 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hRXQL-00036T-D8; Fri, 17 May 2019 07:37:03 +0000 X-UUID: e5ced39b58f346c4828cc3da6dddcf93-20190516 X-UUID: e5ced39b58f346c4828cc3da6dddcf93-20190516 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLS) with ESMTP id 659267913; Thu, 16 May 2019 23:36:46 -0800 Received: from mtkmbs03n1.mediatek.inc (172.21.101.181) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 17 May 2019 00:36:45 -0700 Received: from MTKCAS36.mediatek.inc (172.27.4.186) by mtkmbs03n1.mediatek.inc (172.21.101.181) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 17 May 2019 15:36:43 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS36.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Fri, 17 May 2019 15:36:42 +0800 Message-ID: <1558078602.14150.27.camel@mhfsdcap03> Subject: Re: [PATCH 4/4] serial: 8250-mtk: modify uart DMA rx From: Long Cheng To: Nicolas Boichat Date: Fri, 17 May 2019 15:36:42 +0800 In-Reply-To: References: <1556336193-15198-1-git-send-email-long.cheng@mediatek.com> <1556336193-15198-5-git-send-email-long.cheng@mediatek.com> X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190517_003701_449228_CDB582C1 X-CRM114-Status: GOOD ( 24.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, Ryder Lee , Zhenbao Liu , linux-serial@vger.kernel.org, srv_heupstream , Greg Kroah-Hartman , Randy Dunlap , lkml , Sean Wang , YT Shen , dmaengine@vger.kernel.org, Vinod Koul , Rob Herring , "moderated list:ARM/Mediatek SoC support" , Sean Wang , Jiri Slaby , Matthias Brugger , Yingjoe Chen , Dan Williams , linux-arm Mailing List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 2019-05-15 at 21:48 +0800, Nicolas Boichat wrote: > On Sat, Apr 27, 2019 at 11:36 AM Long Cheng wrote: > > > > Modify uart rx and complete for DMA. > > I don't know much about the DMA framework, but can you please explain > why you are making the changes in this CL? I see that you are dropping > dma_sync_single_for_device calls, for example, why? > the rx buffer is create by 'dma_alloc_coherent'. in the function, the buffer is uncache. We don't need to sync between CPU and DMA. So I remove it. > > > > Signed-off-by: Long Cheng > > --- > > drivers/tty/serial/8250/8250_mtk.c | 53 ++++++++++++++++-------------------- > > 1 file changed, 23 insertions(+), 30 deletions(-) > > > > diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c > > index c1fdbc0..04081a6 100644 > > --- a/drivers/tty/serial/8250/8250_mtk.c > > +++ b/drivers/tty/serial/8250/8250_mtk.c > > @@ -30,7 +30,6 @@ > > #define MTK_UART_DMA_EN_TX 0x2 > > #define MTK_UART_DMA_EN_RX 0x5 > > > > -#define MTK_UART_TX_SIZE UART_XMIT_SIZE > > #define MTK_UART_RX_SIZE 0x8000 > > #define MTK_UART_TX_TRIGGER 1 > > #define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE > > @@ -64,28 +63,30 @@ static void mtk8250_dma_rx_complete(void *param) > > struct mtk8250_data *data = up->port.private_data; > > struct tty_port *tty_port = &up->port.state->port; > > struct dma_tx_state state; > > + int copied, cnt, tmp; > > unsigned char *ptr; > > - int copied; > > > > - dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr, > > - dma->rx_size, DMA_FROM_DEVICE); > > + if (data->rx_status == DMA_RX_SHUTDOWN) > > + return; > > > > dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); > > + cnt = dma->rx_size - state.residue; > > + tmp = cnt; > > I ponder, maybe we should rename cnt to left? (like, how many bytes > are left to transfer, in total) Or maybe "total" > Then maybe rename tmp to cnt. > like better. > > > > - if (data->rx_status == DMA_RX_SHUTDOWN) > > - return; > > + if ((data->rx_pos + cnt) > dma->rx_size) > > + tmp = dma->rx_size - data->rx_pos; > > Maybe replace this and the line above: > tmp = max_t(int, cnt, dma->rx_size - data->rx_pos); > Yes. It's better. > > > > - if ((data->rx_pos + state.residue) <= dma->rx_size) { > > - ptr = (unsigned char *)(data->rx_pos + dma->rx_buf); > > - copied = tty_insert_flip_string(tty_port, ptr, state.residue); > > - } else { > > - ptr = (unsigned char *)(data->rx_pos + dma->rx_buf); > > - copied = tty_insert_flip_string(tty_port, ptr, > > - dma->rx_size - data->rx_pos); > > + ptr = (unsigned char *)(data->rx_pos + dma->rx_buf); > > + copied = tty_insert_flip_string(tty_port, ptr, tmp); > > + data->rx_pos += tmp; > > + > > + if (cnt > tmp) { > > ptr = (unsigned char *)(dma->rx_buf); > > - copied += tty_insert_flip_string(tty_port, ptr, > > - data->rx_pos + state.residue - dma->rx_size); > > + tmp = cnt - tmp; > > + copied += tty_insert_flip_string(tty_port, ptr, tmp); > > + data->rx_pos = tmp; > > } > > + > > up->port.icount.rx += copied; > > > > tty_flip_buffer_push(tty_port); > > @@ -96,9 +97,7 @@ static void mtk8250_dma_rx_complete(void *param) > > static void mtk8250_rx_dma(struct uart_8250_port *up) > > { > > struct uart_8250_dma *dma = up->dma; > > - struct mtk8250_data *data = up->port.private_data; > > struct dma_async_tx_descriptor *desc; > > - struct dma_tx_state state; > > > > desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr, > > dma->rx_size, DMA_DEV_TO_MEM, > > @@ -113,12 +112,6 @@ static void mtk8250_rx_dma(struct uart_8250_port *up) > > > > dma->rx_cookie = dmaengine_submit(desc); > > > > - dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); > > - data->rx_pos = state.residue; > > - > > - dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr, > > - dma->rx_size, DMA_FROM_DEVICE); > > - > > dma_async_issue_pending(dma->rxchan); > > } > > > > @@ -131,13 +124,13 @@ static void mtk8250_dma_enable(struct uart_8250_port *up) > > if (data->rx_status != DMA_RX_START) > > return; > > > > - dma->rxconf.direction = DMA_DEV_TO_MEM; > > - dma->rxconf.src_addr_width = dma->rx_size / 1024; > > - dma->rxconf.src_addr = dma->rx_addr; > > + dma->rxconf.direction = DMA_DEV_TO_MEM; > > + dma->rxconf.src_port_window_size = dma->rx_size; > > + dma->rxconf.src_addr = dma->rx_addr; > > > > - dma->txconf.direction = DMA_MEM_TO_DEV; > > - dma->txconf.dst_addr_width = MTK_UART_TX_SIZE / 1024; > > - dma->txconf.dst_addr = dma->tx_addr; > > + dma->txconf.direction = DMA_MEM_TO_DEV; > > + dma->txconf.dst_port_window_size = UART_XMIT_SIZE; > > + dma->txconf.dst_addr = dma->tx_addr; > > > > serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | > > UART_FCR_CLEAR_XMIT); > > @@ -217,7 +210,7 @@ static void mtk8250_shutdown(struct uart_port *port) > > * Mediatek UARTs use an extra highspeed register (UART_MTK_HIGHS) > > * > > * We need to recalcualte the quot register, as the claculation depends > > - * on the vaule in the highspeed register. > > + * on the value in the highspeed register. > > Since you're doing some cosmetic changes here, you might as well fix > recalcualte => recalculate and claculation => calculation on the line > above. > I see. > But technically, this should belong in another patch... > > > * > > * Some baudrates are not supported by the chip, so we use the next > > * lower rate supported and update termios c_flag. > > -- > > 1.7.9.5 > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel