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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAF78CDB482 for ; Mon, 16 Oct 2023 09:02:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233099AbjJPJC0 (ORCPT ); Mon, 16 Oct 2023 05:02:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233188AbjJPJCL (ORCPT ); Mon, 16 Oct 2023 05:02:11 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B2D6118 for ; Mon, 16 Oct 2023 02:02:09 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B927C433C7; Mon, 16 Oct 2023 09:02:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1697446929; bh=yGHRDJmF+TNSGBd1Dm8votEx6BuNR8h03JDvo/ZLcN8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=11/83vkcDPdoUBE0FmKGkkJYWfBCegOzll+fg/+5R1a3RO3hnqA7jS4jNN5nBW5ee j7DY6xEJU3V4Nw5QkQ9UHKM0omhCKy8yhdl+ZHrVP1W2UJWIr325FGgOuGo8Cbud0E 6H8r7faklJhu+0fkMzN93MgNww7p1haTNds8AUeE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Amelie Delaunay , Vinod Koul Subject: [PATCH 6.1 071/131] dmaengine: stm32-mdma: use Link Address Register to compute residue Date: Mon, 16 Oct 2023 10:40:54 +0200 Message-ID: <20231016084001.828078621@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231016084000.050926073@linuxfoundation.org> References: <20231016084000.050926073@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amelie Delaunay commit a4b306eb83579c07b63dc65cd5bae53b7b4019d0 upstream. Current implementation relies on curr_hwdesc index. But to keep this index up to date, Block Transfer interrupt (BTIE) has to be enabled. If it is not, curr_hwdesc is not updated, and then residue is not reliable. Rely on Link Address Register instead. And disable BTIE interrupt in stm32_mdma_setup_xfer() because it is no more needed in case of _prep_slave_sg() to maintain curr_hwdesc up to date. It avoids extra interrupts and also ensures a reliable residue. These improvements are required for STM32 DCMI camera capture use case, which need STM32 DMA and MDMA chaining for good performance. Fixes: 696874322771 ("dmaengine: stm32-mdma: add support to be triggered by STM32 DMA") Signed-off-by: Amelie Delaunay Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231004163531.2864160-2-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/stm32-mdma.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/drivers/dma/stm32-mdma.c +++ b/drivers/dma/stm32-mdma.c @@ -778,8 +778,6 @@ static int stm32_mdma_setup_xfer(struct /* Enable interrupts */ ccr &= ~STM32_MDMA_CCR_IRQ_MASK; ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE; - if (sg_len > 1) - ccr |= STM32_MDMA_CCR_BTIE; desc->ccr = ccr; return 0; @@ -1325,12 +1323,21 @@ static size_t stm32_mdma_desc_residue(st { struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan); struct stm32_mdma_hwdesc *hwdesc; - u32 cbndtr, residue, modulo, burst_size; + u32 cisr, clar, cbndtr, residue, modulo, burst_size; int i; + cisr = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id)); + residue = 0; - for (i = curr_hwdesc + 1; i < desc->count; i++) { + /* Get the next hw descriptor to process from current transfer */ + clar = stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id)); + for (i = desc->count - 1; i >= 0; i--) { hwdesc = desc->node[i].hwdesc; + + if (hwdesc->clar == clar) + break;/* Current transfer found, stop cumulating */ + + /* Cumulate residue of unprocessed hw descriptors */ residue += STM32_MDMA_CBNDTR_BNDT(hwdesc->cbndtr); } cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));