From patchwork Thu May 5 10:26:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amelie Delaunay X-Patchwork-Id: 12839354 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 D2994C433FE for ; Thu, 5 May 2022 10:27:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355518AbiEEKax (ORCPT ); Thu, 5 May 2022 06:30:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240927AbiEEKav (ORCPT ); Thu, 5 May 2022 06:30:51 -0400 Received: from mx07-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B2A6517F3; Thu, 5 May 2022 03:27:12 -0700 (PDT) Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 2458U01o001536; Thu, 5 May 2022 12:26:55 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=selector1; bh=vVNs20GHeQv8C1KNCWf/owN4D8dQJUtAlbOROVhSK7s=; b=iQG1ip0qqrP1rdEbmOo7sq9Ff8CNH0nyRCr6NRFJmYoExKiWYmwj+qhRRthhWvWlmv1i 07s9xSGfq36kI/b/IbXRuzDXC5hd4HIXjHA21fAWcil5le8Ab0XG3rtR7y5w1jz3Fw8r ByUzC7pgW8SZXNiBftmmbRZAvlQ4QIgHsRtq5IMYtzZL6MhFZ/ZmBgN9KTpnVeY6dUJg k8J/VTUX7eY+86H0GzWRKHJBCuDSpuyAgOwAiLcjO5rojDGyhgQycqRf2GNDVG0w7k1C 3AishfqbiUCQn2+txFk24+76FqV9ypVWNT8n7+tDe00+mMlO4CZ89t7gB2F/8qdFwNyB ZA== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3frv0gjx2r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 05 May 2022 12:26:55 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id D518B100034; Thu, 5 May 2022 12:26:54 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id CD84A2171CE; Thu, 5 May 2022 12:26:54 +0200 (CEST) Received: from localhost (10.75.127.51) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Thu, 5 May 2022 12:26:54 +0200 From: Amelie Delaunay To: Vinod Koul , Maxime Coquelin , Alexandre Torgue CC: , , , , Amelie Delaunay Subject: [PATCH 1/4] dmaengine: stm32-dma: introduce stm32_dma_sg_inc to manage chan->next_sg Date: Thu, 5 May 2022 12:26:33 +0200 Message-ID: <20220505102636.35506-2-amelie.delaunay@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220505102636.35506-1-amelie.delaunay@foss.st.com> References: <20220505102636.35506-1-amelie.delaunay@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.51] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-05_04,2022-05-05_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org chan->next_sg is used to know which transfer will start after the ongoing one. It is incremented for each new transfer, either on transfer start for non-cyclic transfers, or on transfer complete interrupt for cyclic transfers. For cyclic transfer, when the last item is reached, chan->next_sg must be reinitialized to the first item. Signed-off-by: Amelie Delaunay --- drivers/dma/stm32-dma.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index d2365fab1b7a..5afe4205f57b 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -535,6 +535,13 @@ static void stm32_dma_dump_reg(struct stm32_dma_chan *chan) dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr); } +static void stm32_dma_sg_inc(struct stm32_dma_chan *chan) +{ + chan->next_sg++; + if (chan->desc->cyclic && (chan->next_sg == chan->desc->num_sgs)) + chan->next_sg = 0; +} + static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan); static void stm32_dma_start_transfer(struct stm32_dma_chan *chan) @@ -575,7 +582,7 @@ static void stm32_dma_start_transfer(struct stm32_dma_chan *chan) stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar); stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr); - chan->next_sg++; + stm32_dma_sg_inc(chan); /* Clear interrupt status if it is there */ status = stm32_dma_irq_status(chan); @@ -606,9 +613,6 @@ static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan) dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id)); if (dma_scr & STM32_DMA_SCR_DBM) { - if (chan->next_sg == chan->desc->num_sgs) - chan->next_sg = 0; - sg_req = &chan->desc->sg_req[chan->next_sg]; if (dma_scr & STM32_DMA_SCR_CT) { @@ -630,7 +634,7 @@ static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan) if (chan->desc) { if (chan->desc->cyclic) { vchan_cyclic_callback(&chan->desc->vdesc); - chan->next_sg++; + stm32_dma_sg_inc(chan); stm32_dma_configure_next_sg(chan); } else { chan->busy = false;