From: vinod.koul@linux.intel.com (Vinod Koul)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 08/13] mmc: omap_hsmmc: limit max_segs with the EDMA DMAC
Date: Thu, 27 Sep 2012 15:11:08 +0530 [thread overview]
Message-ID: <1348738868.1648.13.camel@vkoul-udesk3> (raw)
In-Reply-To: <20120921184721.GD31374@n2100.arm.linux.org.uk>
On Fri, 2012-09-21 at 19:47 +0100, Russell King - ARM Linux wrote:
> On Fri, Sep 21, 2012 at 10:45:29PM +0530, S, Venkatraman wrote:
> > On Thu, Sep 20, 2012 at 8:13 PM, Matt Porter <mporter@ti.com> wrote:
> > > The EDMA DMAC has a hardware limitation that prevents supporting
> > > scatter gather lists with any number of segments. Since the EDMA
> > > DMA Engine driver sets the maximum segments to 16, we do the
> > > same.
> > >
> > > Note: this can be removed once the DMA Engine API supports an
> > > API to query the DMAC's segment limitations.
> > >
> >
> > I wouldn't want to bind the properties of EDMA to omap_hsmmc as this patch
> > suggests. Why don't we have a max_segs property, which when explicitly specified
> > in DT, will override the default ?
>
> Why not have a generic way that DMA engine can export these kinds of
> properties?
We discussed this at KS. I was of opinion that DMA engine should export
controller and channel capabilities as part of the channel it returns.
Some folks had an opinion that they already know how to use controller
so may not be very helpful, but if it is going to help (which I think),
i have a patch for this :)
--
~Vinod
next prev parent reply other threads:[~2012-09-27 9:41 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-20 14:43 [RFC PATCH 00/13] DMA Engine support for AM33xx Matt Porter
2012-09-20 14:43 ` [RFC PATCH 01/13] ARM: davinci: move private EDMA API to arm/common Matt Porter
2012-09-21 7:10 ` Hebbar, Gururaja
2012-09-21 18:24 ` Matt Porter
2012-09-21 9:29 ` Russell King - ARM Linux
2012-09-21 9:33 ` Hebbar, Gururaja
2012-09-21 9:42 ` Russell King - ARM Linux
2012-09-21 18:34 ` Matt Porter
2012-09-21 18:50 ` Russell King - ARM Linux
2012-09-24 2:44 ` Hebbar, Gururaja
2012-09-20 14:43 ` [RFC PATCH 02/13] ARM: edma: remove unused transfer controller handlers Matt Porter
2012-09-20 14:43 ` [RFC PATCH 03/13] ARM: edma: add DT and runtime PM support for AM335x Matt Porter
2012-09-21 8:53 ` Hebbar, Gururaja
2012-10-09 18:58 ` Matt Porter
2012-09-20 14:43 ` [RFC PATCH 04/13] dmaengine: edma: enable build " Matt Porter
2012-09-20 14:43 ` [RFC PATCH 05/13] dma: Add TI EDMA device tree binding Matt Porter
2012-09-21 8:45 ` Hebbar, Gururaja
2012-09-21 18:23 ` Matt Porter
2012-09-20 14:43 ` [RFC PATCH 06/13] ARM: omap: add hsmmc am33xx specific init Matt Porter
2012-09-20 14:43 ` [RFC PATCH 07/13] mmc: omap_hsmmc: dma_request_slave_channel() support for DT platforms Matt Porter
2012-09-20 22:16 ` Tony Lindgren
2012-09-20 14:43 ` [RFC PATCH 08/13] mmc: omap_hsmmc: limit max_segs with the EDMA DMAC Matt Porter
2012-09-21 17:15 ` S, Venkatraman
2012-09-21 17:17 ` S, Venkatraman
2012-09-21 17:18 ` Felipe Balbi
2012-09-21 17:33 ` S, Venkatraman
2012-09-21 18:54 ` Matt Porter
2012-09-21 18:42 ` Matt Porter
2012-09-21 18:47 ` Russell King - ARM Linux
2012-09-21 19:03 ` Matt Porter
2012-09-27 9:41 ` Vinod Koul [this message]
2012-10-01 16:39 ` Matt Porter
2012-10-02 12:03 ` Vinod Koul
2012-09-20 14:43 ` [RFC PATCH 09/13] mmc: omap_hsmmc: add generic DMA request support to the DT binding Matt Porter
2012-09-20 14:43 ` [RFC PATCH 10/13] spi: omap2-mcspi: dma_request_slave_channel() support for DT platforms Matt Porter
2012-09-20 22:09 ` Tony Lindgren
2012-09-21 8:16 ` Arnd Bergmann
2012-09-21 15:42 ` Tony Lindgren
2012-09-21 18:37 ` Matt Porter
2012-09-27 9:36 ` Vinod Koul
2012-10-01 16:37 ` Matt Porter
2012-09-20 14:43 ` [RFC PATCH 11/13] spi: omap2-mcspi: add generic DMA request support to the DT binding Matt Porter
2012-09-20 14:43 ` [RFC PATCH 12/13] ARM: dts: add am33xx EDMA support Matt Porter
2012-09-20 14:43 ` [RFC PATCH 13/13] Documentation: add schedule for removing private EDMA API Matt Porter
2012-09-20 15:58 ` Mark Brown
2012-09-20 16:05 ` Matt Porter
2012-09-21 8:27 ` [RFC PATCH 00/13] DMA Engine support for AM33xx Hebbar, Gururaja
2012-09-21 18:22 ` Matt Porter
2012-09-24 11:26 ` Hebbar, Gururaja
2012-09-24 12:05 ` Matt Porter
2012-09-26 8:26 ` Hebbar, Gururaja
2012-09-26 13:01 ` Matt Porter
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