From nobody Wed Nov 27 13:39:07 2024 Received: from mx07-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 993A81F892A; Thu, 10 Oct 2024 14:31:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.207.212.93 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728570710; cv=none; b=bw2st9MZhiAbgHd+cVmo7PVKm0YHRD0lQIHWe4cZQ/bV76T6clIiYetaouqpFqCqjv4v8CDz33cKsFzVQXaYC6dI2tgHcvxjTWzF2mNF4xykpbnmDaDe669Z3LxtvHf/eJsiHCfKmXBN92OaZzAVkU2eyGu0Q6Z2jVp5vCvl8Xs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728570710; c=relaxed/simple; bh=5b5rfrygcx7Qo9y6A9GF0vdCRsrnMPdtDmlEDViOX1s=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=AVPNqLMeYr24YRHqmOR0awO/1xUpmCfHFaWpTC5dlqjcAlZ+zBzWcaFROtVGs4Kelvy6gdJIQwE0Y7IL4KcEewGhrk1VCCG+tVqQ+6XSkLQVrexqXACFVp/0LHgL/CaA7a+r3T+TVacVVuEr7cLd+/AEXmAgcct/ojCo+zmEwe8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foss.st.com; spf=pass smtp.mailfrom=foss.st.com; dkim=pass (2048-bit key) header.d=foss.st.com header.i=@foss.st.com header.b=pVhB0R01; arc=none smtp.client-ip=91.207.212.93 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foss.st.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=foss.st.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=foss.st.com header.i=@foss.st.com header.b="pVhB0R01" Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49AEMAQA014760; Thu, 10 Oct 2024 16:31:33 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=selector1; bh= 8zvSJPaOxFyx6iKmFarEMp7/qdMh7rTZXLJBCgsAQ4g=; b=pVhB0R01g1VunsM7 vmZThmKunyzqYZk7aV16FlLXg4imz4TEuz0xxLJ7s2+FeN2uDyQWhA1rW7c8YkrO 6t3sxtH96U5OhtHWFK8OXhIPoJ40VkZuBz9I6W1lXxhNCODOga6PvP2G8qxHzkbm VIo7rSPsRY1u8EEPvfJkMQii2WP6TLi0FXPazeY4zntqkxyNVn6KbybjMz3q8wLA 8W2G15DzxX6LxQeJWmn3XiEubR1Y2Q/2eYSgQ0HMvZtwjBKbuNnWGblvspJ9RwD1 GmRqj28CflRGlTka8FT5jY3i7HLB8ZUT9tdw+wp4OuoiTEqvs8C5jJ298RlAGVO7 suXOWA== Received: from beta.dmz-ap.st.com (beta.dmz-ap.st.com [138.198.100.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 425q97xxb5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 10 Oct 2024 16:31:33 +0200 (MEST) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id 5486940069; Thu, 10 Oct 2024 16:30:21 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node3.st.com [10.75.129.71]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 2464D2954A5; Thu, 10 Oct 2024 16:28:07 +0200 (CEST) Received: from localhost (10.252.31.182) by SHFDAG1NODE3.st.com (10.75.129.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.37; Thu, 10 Oct 2024 16:28:06 +0200 From: Amelie Delaunay Date: Thu, 10 Oct 2024 16:27:51 +0200 Subject: [PATCH 01/11] dt-bindings: dma: stm32-dma3: prevent packing/unpacking mode Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-ID: <20241010-dma3-mp25-updates-v1-1-adf0633981ea@foss.st.com> References: <20241010-dma3-mp25-updates-v1-0-adf0633981ea@foss.st.com> In-Reply-To: <20241010-dma3-mp25-updates-v1-0-adf0633981ea@foss.st.com> To: Vinod Koul , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Maxime Coquelin , Alexandre Torgue CC: , , , , , Amelie Delaunay X-Mailer: b4 0.14.2 X-ClientProxiedBy: SHFCAS1NODE1.st.com (10.75.129.72) To SHFDAG1NODE3.st.com (10.75.129.71) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 When source data width/burst and destination data width/burst are different, data are packed or unpacked in DMA3 channel FIFO. Data are pushed out from DMA3 channel FIFO when the destination burst length (=3D data width * burst) is reached. If the channel is stopped before the transfer end, and if some bytes are packed/unpacked in the DMA3 channel FIFO, these bytes are lost. Indeed, DMA3 channel FIFO has no flush capability, only reset. To avoid potential bytes lost, pack/unpack must be prevented by setting memory data width/burst equal to peripheral data width/burst. Memory accesses will be penalized. But it is the only way to avoid bytes lost. Some devices (e.g. cyclic RX like UART) need this, so add the possibility to prevent pack/unpack feature, by setting bit 16 of the 'DMA transfer requirements' bit mask. Signed-off-by: Amelie Delaunay Acked-by: Rob Herring (Arm) --- Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml= b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml index 7fdc44b2e6467928622a5bb25d9e0c74bb1790ae..5484848735f8ac3d2050104bbab= 1d986e82ba6a7 100644 --- a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml +++ b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml @@ -96,6 +96,9 @@ properties: including the update of the LLI if any 0x3: at channel level, the transfer complete event is generated = at the end of the last LLI + -bit 16: Prevent packing/unpacking mode + 0x0: pack/unpack enabled when source data width/burst !=3D desti= nation data width/burst + 0x1: memory data width/burst forced to peripheral data width/bur= st to prevent pack/unpack =20 required: - compatible --=20 2.25.1