From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (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 25BF8480DC0 for ; Wed, 6 May 2026 14:01:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778076111; cv=none; b=hfMSnAhW5BhbbCppkcsuTuFLbfO1AFcE6/05Qj3MKAfLYJg20528bQluHYQ8fiqJ92XkJQCjm28isY3NIpqBiEJVRLX93U5u3v+KCJnGWOxe81AFq/tpXTSdR+KLjMEXLRFUakV166NiIQwsnOUNqv9tZVkG7i87RYc4UEOkx4Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778076111; c=relaxed/simple; bh=pw5M7wHyJF7qGE8EOkabTS3y0p6s5JDD1IostcxlSv4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nib/LP8lGj1U9XB4ELtGo1OYJYGItvTeMU3TpySm/kfHe1g9cN+d0hB4g8Ki/nYxWzA+tMJFqNygR7O+6A9NAMkTZ6pb7YMWS8dtTowzc0lJiCA7UHazioijRPlpEGRPL8K82nVQcGxf8h5hhHcKoDGEOC2Jydy2lZfuml0KrWE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=E0GFlRfg; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="E0GFlRfg" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id D31BA4E42C03; Wed, 6 May 2026 14:01:42 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id A74CE6053C; Wed, 6 May 2026 14:01:42 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 6FB89107F1B59; Wed, 6 May 2026 16:01:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1778076100; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=8VpBetH3FnMFpP2ml6zi3fZvsO0QOprxF497sdCPnpM=; b=E0GFlRfgdvdfui6wsFff2FGJz4F3OVteevBzZRDss8yVpWUh1wped7N0f7uVaAupIDnbr4 8Mc88MlkQGntEj0sowal1DfNFSuHRORrCiGp0D6wyHk74AFoNTZ6EC1yuRUgAZSkbQFp8C K1NZSsKqPIU2q2hTksznzNHzCCsCWzHFcYiDrCNjxJbPSDWrM+VDAvpRoOqmwDkP6J2UVE 6WLKHN7x1Tg2KfFQ4ReQIDwvC7OSi8HG5/Aj3YOUfyXWJIxkQuB6N7t2BO3Ohe1potTaQd YAbscpQGxaiFP/fje6S6tflDZ84gnB0hdVsfOXjnr5T3lL/vr9d2+Q2xCgZ0rw== From: =?UTF-8?B?QmVub8OudA==?= Monin To: Frank Li Cc: Vinod Koul , Thomas Petazzoni , Frank Li , imx@lists.linux.dev, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 2/2] dmaengine: fsl-edma: Support dynamic scatter/gather chaining Date: Wed, 06 May 2026 16:01:37 +0200 Message-ID: <43uRGEDfSHihWPAxby2EOg@bootlin.com> In-Reply-To: References: <20260430-fsl-edma-dyn-sg-v1-0-4e0ecbe2df66@bootlin.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-Last-TLS-Session-Version: TLSv1.3 On Tuesday, 5 May 2026 at 17:07:48 CEST, Frank Li wrote: > > > how do you test it? and how much preformance improved? > > I did my tests by doing SPI transfers with the LPSPI controllers, doing= DMA > > transactions with different number of buffers and different buffer size= s. > > Without chaining, interruptions on the SPI bus occur between each DMA > > transaction. With chaining, the activity on the SPI bus is continuous as > > long as DMA transactions are issued before the end of the current > > transaction. >=20 > Does SPI support issue new transfers without wait for previous transfer > complete, or SPI transfer already support async queue? >=20 This is done with a local version of fsl-lpspi driver adding a simple offload support by borrowing the DMA channels allocated to the SPI controller. I can then issue multiple DMA transactions with the dma_buf API of the IIO subsystem and trigger SG chaining. Best regards, =2D-=20 Beno=C3=AEt Monin, Bootlin Embedded Linux and Kernel engineering https://bootlin.com