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[209.132.180.67]) by mx.google.com with ESMTP id c7-v6si274302plo.432.2018.03.13.09.48.20; Tue, 13 Mar 2018 09:48:34 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933433AbeCMQmq (ORCPT + 99 others); Tue, 13 Mar 2018 12:42:46 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:59850 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752892AbeCMQmm (ORCPT ); Tue, 13 Mar 2018 12:42:42 -0400 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx08-.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id w2DGcpIS000362; Tue, 13 Mar 2018 17:42:18 +0100 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx08-00178001.pphosted.com with ESMTP id 2gpc6wa1mn-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Tue, 13 Mar 2018 17:42:18 +0100 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 8EFB134; Tue, 13 Mar 2018 16:42:17 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag5node2.st.com [10.75.127.14]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 6B662A675; Tue, 13 Mar 2018 16:42:17 +0000 (GMT) Received: from localhost (10.75.127.46) by SFHDAG5NODE2.st.com (10.75.127.14) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Tue, 13 Mar 2018 17:42:16 +0100 From: Pierre-Yves MORDRET To: Vinod Koul , Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre Torgue , Dan Williams , "M'boumba Cedric Madianga" , , , , CC: Pierre-Yves MORDRET Subject: [PATCH v1 5/8] dmaengine: stm32-dma: fix max items per transfer Date: Tue, 13 Mar 2018 17:42:04 +0100 Message-ID: <1520959327-25760-6-git-send-email-pierre-yves.mordret@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1520959327-25760-1-git-send-email-pierre-yves.mordret@st.com> References: <1520959327-25760-1-git-send-email-pierre-yves.mordret@st.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.75.127.46] X-ClientProxiedBy: SFHDAG1NODE3.st.com (10.75.127.3) To SFHDAG5NODE2.st.com (10.75.127.14) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-13_07:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Having 0 in item counter register is valid and stands for a "No or Ended transfer". Therefore valid transfer starts from @+0 to @+0xFFFE leading to unaligned scatter gather at boundary. Thus it's safer to round down this value on its FIFO size (16 Bytes). Signed-off-by: Pierre-Yves MORDRET --- Version history: v1: * Initial --- --- drivers/dma/stm32-dma.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index 0685961..f9d3c84 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -38,10 +38,6 @@ #define STM32_DMA_TEI BIT(3) /* Transfer Error Interrupt */ #define STM32_DMA_DMEI BIT(2) /* Direct Mode Error Interrupt */ #define STM32_DMA_FEI BIT(0) /* FIFO Error Interrupt */ -#define STM32_DMA_MASKI (STM32_DMA_TCI \ - | STM32_DMA_TEI \ - | STM32_DMA_DMEI \ - | STM32_DMA_FEI) /* DMA Stream x Configuration Register */ #define STM32_DMA_SCR(x) (0x0010 + 0x18 * (x)) /* x = 0..7 */ @@ -117,6 +113,13 @@ #define STM32_DMA_FIFO_THRESHOLD_FULL 0x03 #define STM32_DMA_MAX_DATA_ITEMS 0xffff +/* + * Valid transfer starts from @0 to @0xFFFE leading to unaligned scatter + * gather at boundary. Thus it's safer to round down this value on FIFO + * size (16 Bytes) + */ +#define STM32_DMA_ALIGNED_MAX_DATA_ITEMS \ + ALIGN_DOWN(STM32_DMA_MAX_DATA_ITEMS, 16) #define STM32_DMA_MAX_CHANNELS 0x08 #define STM32_DMA_MAX_REQUEST_ID 0x08 #define STM32_DMA_MAX_DATA_PARAM 0x03 @@ -864,7 +867,7 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg( desc->sg_req[i].len = sg_dma_len(sg); nb_data_items = desc->sg_req[i].len / buswidth; - if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) { + if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) { dev_err(chan2dev(chan), "nb items not supported\n"); goto err; } @@ -930,7 +933,7 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic( return NULL; nb_data_items = period_len / buswidth; - if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) { + if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) { dev_err(chan2dev(chan), "number of items not supported\n"); return NULL; } @@ -980,7 +983,7 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy( u32 num_sgs, best_burst, dma_burst, threshold; int i; - num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS); + num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS); desc = stm32_dma_alloc_desc(num_sgs); if (!desc) return NULL; @@ -989,7 +992,7 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy( for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) { xfer_count = min_t(size_t, len - offset, - STM32_DMA_MAX_DATA_ITEMS); + STM32_DMA_ALIGNED_MAX_DATA_ITEMS); /* Compute best burst size */ max_width = DMA_SLAVE_BUSWIDTH_1_BYTE; -- 2.7.4