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From: Kevin Hilman <khilman@baylibre.com>
To: David Lechner <david@lechnology.com>
Cc: Mark Brown <broonie@kernel.org>,
	nsekhar@ti.com, linux-spi@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RESEND] spi: davinci: Allow device tree devices to use DMA
Date: Thu, 12 Jan 2017 13:34:10 -0800	[thread overview]
Message-ID: <m24m146jzh.fsf@baylibre.com> (raw)
In-Reply-To: <1483673177-31516-1-git-send-email-david@lechnology.com> (David Lechner's message of "Thu, 5 Jan 2017 21:26:17 -0600")

David Lechner <david@lechnology.com> writes:

> This allows SPI devices specified in a device tree to use DMA when the
> master controller.

Enabling DMA for spi-davinci isn't quite ready yet since this driver is
blindly using dma_map_single() on addresses passed in.  MTD seems to use
vmalloc'd buffers, which cannot be passed direclty to dma_map_single().

I thinks this driver needs an update to use spi_map_buf() to be able to
handle vmalloc'd buffers before always enabling DMA.

Kevin

WARNING: multiple messages have this Message-ID (diff)
From: khilman@baylibre.com (Kevin Hilman)
To: linux-arm-kernel@lists.infradead.org
Subject: [RESEND] spi: davinci: Allow device tree devices to use DMA
Date: Thu, 12 Jan 2017 13:34:10 -0800	[thread overview]
Message-ID: <m24m146jzh.fsf@baylibre.com> (raw)
In-Reply-To: <1483673177-31516-1-git-send-email-david@lechnology.com> (David Lechner's message of "Thu, 5 Jan 2017 21:26:17 -0600")

David Lechner <david@lechnology.com> writes:

> This allows SPI devices specified in a device tree to use DMA when the
> master controller.

Enabling DMA for spi-davinci isn't quite ready yet since this driver is
blindly using dma_map_single() on addresses passed in.  MTD seems to use
vmalloc'd buffers, which cannot be passed direclty to dma_map_single().

I thinks this driver needs an update to use spi_map_buf() to be able to
handle vmalloc'd buffers before always enabling DMA.

Kevin

  parent reply	other threads:[~2017-01-12 21:34 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-06  3:26 [RESEND] spi: davinci: Allow device tree devices to use DMA David Lechner
2017-01-06  3:26 ` David Lechner
2017-01-06  3:26 ` David Lechner
     [not found] ` <1483673177-31516-1-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2017-01-09 19:48   ` Mark Brown
2017-01-09 19:48     ` Mark Brown
2017-01-09 19:48     ` Mark Brown
     [not found]     ` <20170109194811.p3if5pzvjjaez2g3-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2017-01-09 20:40       ` David Lechner
2017-01-09 20:40         ` David Lechner
2017-01-09 20:40         ` David Lechner
2017-01-10 16:51         ` Mark Brown
2017-01-10 16:51           ` Mark Brown
2017-01-10 16:51           ` Mark Brown
2017-01-12 21:34 ` Kevin Hilman [this message]
2017-01-12 21:34   ` Kevin Hilman
2017-01-13 12:04   ` Mark Brown
2017-01-13 12:04     ` Mark Brown
2017-01-13 12:04     ` Mark Brown

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