From nobody Wed Nov 27 13:51:26 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 623CE1F7069; Thu, 10 Oct 2024 14:31:46 +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=1728570709; cv=none; b=a+Ikfh3eSeosKCaNDmK9DZv3Hc+ZWMIth+BG3Mj8fhh42LbuF9RIzaGbm277qvugZDRTuOJdFixs+tdzVQS2WqtvEczqjDaSCoM6hJk6mom1s7syWaYB44me3hi6FRb/BOoR4KuBu/CRx7lFCya1Di34xdQOSlw0BobK7uXVJF0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728570709; c=relaxed/simple; bh=M+OwuR2L3A1nuRrWpdlwUD5uHBzx8kDYo55SfadjvxE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=K0DMNzZ0+KNpwR5UPt3hkUN5fUfFB0wZxMeLBstfsDWP33kYgASFjU1/Hi3LRvGS0S2ysqqETnkeWClfY+QM7hPbwt7TXUl12ucPHBDQQ5POg7psA1cUjh/4m28mCvh01SCD+JMoy1o2YBY97OVCi+z2zNeuctDoYjuMBkbPDPY= 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=m5qs6jeh; 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="m5qs6jeh" Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49AE78eZ014745; 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= cB08zjQih/Ih6h2EceQOGpBZJJTkTNDk33t9blGD3t4=; b=m5qs6jehLgxPnCWR DkX+TkDcMnZsJhxMwsEwTYZuQND33toHLNPWRbBmb66SqUyuhJwsS1s0YIo9K9LY ivirtQsGbb8+rGvQA7dFwJHTRoc8nVJDFwjzZX8sPkGA1yu8Ehsa9HkW4ZefCWnX W6aCVShpaAPYyFR/sNOV/fjHu3wrpxxQh8Ikt/wKUb4FFIfg4sTpY0ps+pCbHqDL 3wcJA+eoj8iDVWHpK8EYa1QkW/u7Rwed4WbsHTrLN23/D5KyuC3VLefxNbUGlGfX rRjg7uX9YtS5gkqANrzC3sXKh7G/0MkTnbgGeZ8mXBiF9LEHCyJDqLj7lKgUZapz NUgk6A== 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 425w9xcvk6-1 (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 6EEA64008E; Thu, 10 Oct 2024 16:30:22 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node3.st.com [10.75.129.71]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id E6D6B2954B9; 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 16:28:07 +0200 From: Amelie Delaunay Date: Thu, 10 Oct 2024 16:27:52 +0200 Subject: [PATCH 02/11] dmaengine: stm32-dma3: prevent pack/unpack thanks to DT configuration 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-v1-2-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, using CxTR1.PAM. Data are pushed out from DMA3 channel FIFO when the destination burst length (=3D data width * burst) is reached. If the transfer is stopped before CxBR1.BNDT =3D 0, 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. Prevent pack/unpack feature can be activated by setting bit 16 of DMA3 Transfer requirements bitfield (tr_conf) in device tree. Signed-off-by: Amelie Delaunay --- drivers/dma/stm32/stm32-dma3.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c index 0be6e944df6fd5d2a02974085251549d9389a37e..2b4cc479e1a1206fef7fd2808d1= 342048d81e07b 100644 --- a/drivers/dma/stm32/stm32-dma3.c +++ b/drivers/dma/stm32/stm32-dma3.c @@ -221,6 +221,7 @@ enum stm32_dma3_port_data_width { #define STM32_DMA3_DT_BREQ BIT(8) /* CTR2_BREQ */ #define STM32_DMA3_DT_PFREQ BIT(9) /* CTR2_PFREQ */ #define STM32_DMA3_DT_TCEM GENMASK(13, 12) /* CTR2_TCEM */ +#define STM32_DMA3_DT_NOPACK BIT(16) /* CTR1_PAM */ =20 /* struct stm32_dma3_chan .config_set bitfield */ #define STM32_DMA3_CFG_SET_DT BIT(0) @@ -622,6 +623,10 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_c= han *chan, enum dma_transf /* Set source (memory) data width and burst */ sdw =3D stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr= ); sbl_max =3D stm32_dma3_get_max_burst(len, sdw, chan->max_burst); + if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf)) { + sdw =3D ddw; + sbl_max =3D dbl_max; + } =20 _ctr1 |=3D FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw)); _ctr1 |=3D FIELD_PREP(CTR1_SBL_1, sbl_max - 1); @@ -652,6 +657,11 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_c= han *chan, enum dma_transf /* Set destination (memory) data width and burst */ ddw =3D stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr= ); dbl_max =3D stm32_dma3_get_max_burst(len, ddw, chan->max_burst); + if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf) || + ((_ctr2 & CTR2_PFREQ) && ddw > sdw)) { /* Packing to wider ddw not s= upported */ + ddw =3D sdw; + dbl_max =3D sbl_max; + } =20 _ctr1 |=3D FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw)); _ctr1 |=3D FIELD_PREP(CTR1_SBL_1, sbl_max - 1); --=20 2.25.1