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From: "Benoît Monin" <benoit.monin@bootlin.com>
To: Frank Li <Frank.li@nxp.com>
Cc: Vinod Koul <vkoul@kernel.org>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Frank Li <Frank.Li@kernel.org>,
	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	[thread overview]
Message-ID: <43uRGEDfSHihWPAxby2EOg@bootlin.com> (raw)
In-Reply-To: <afoHxJM-s846s6EG@lizhi-Precision-Tower-5810>

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 sizes.
> > 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.
> 
> Does SPI support issue new transfers without wait for previous transfer
> complete, or SPI transfer already support async queue?
> 
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,
-- 
Benoît Monin, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com




  reply	other threads:[~2026-05-06 14:01 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-30  9:49 [PATCH RFC 0/2] dmaengine: fsl-edma: Scatter/gather improvements Benoît Monin
2026-04-30  9:49 ` [PATCH RFC 1/2] dmaengine: fsl-edma: Implement device_prep_peripheral_dma_vec Benoît Monin
2026-05-04 15:58   ` Frank Li
2026-05-05 13:51     ` Benoît Monin
2026-04-30  9:49 ` [PATCH RFC 2/2] dmaengine: fsl-edma: Support dynamic scatter/gather chaining Benoît Monin
2026-05-04 16:04   ` Frank Li
2026-05-05 13:51     ` Benoît Monin
2026-05-05 15:07       ` Frank Li
2026-05-06 14:01         ` Benoît Monin [this message]
2026-05-06 14:48           ` Frank Li

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