From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: [RFC v02 00/15] dmaengine: New 'universal' API for requesting channel Date: Tue, 1 Dec 2015 12:12:47 +0200 Message-ID: <565D729F.2000104@ti.com> References: <1448891145-10766-1-git-send-email-peter.ujfalusi@ti.com> <13562653.8QgTG33tZS@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: , , , , , , , To: Arnd Bergmann , Return-path: In-Reply-To: <13562653.8QgTG33tZS@wuerfel> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On 11/30/2015 04:18 PM, Arnd Bergmann wrote: > On Monday 30 November 2015 15:45:30 Peter Ujfalusi wrote: >> Changes since RFC v01: >> - dma_request_chan(); lost the mask parameter >> - The new API does not rely on RESOURCE_DMA, instead the dma_filter_= map table >> will be used to provide the needed information to the filter functi= on in >> legacy mode >> - Extended the example patches to convert most of daVinci to use the= new API to >> request the DMA channels. >=20 > Very nice overall. Just a few minor comments. >=20 >> static struct dma_filter_map da830_edma_map[] =3D { >> DMA_FILTER_ENTRY("davinci-mcasp.0", "rx", EDMA_CTLR_CHAN(0, = 0)), >> DMA_FILTER_ENTRY("davinci-mcasp.0", "tx", EDMA_CTLR_CHAN(0, = 1)), >> DMA_FILTER_ENTRY("davinci-mcasp.1", "rx", EDMA_CTLR_CHAN(0, = 2)), >> DMA_FILTER_ENTRY("davinci-mcasp.1", "tx", EDMA_CTLR_CHAN(0, = 3)), >> DMA_FILTER_ENTRY("davinci-mcasp.2", "rx", EDMA_CTLR_CHAN(0, = 4)), >> DMA_FILTER_ENTRY("davinci-mcasp.2", "tx", EDMA_CTLR_CHAN(0, = 5)), >> DMA_FILTER_ENTRY("spi_davinci.0", "rx", EDMA_CTLR_CHAN(0, 14= )), >> DMA_FILTER_ENTRY("spi_davinci.0", "tx", EDMA_CTLR_CHAN(0, 15= )), >> DMA_FILTER_ENTRY("da830-mmc.0", "rx", EDMA_CTLR_CHAN(0, 16))= , >> DMA_FILTER_ENTRY("da830-mmc.0", "tx", EDMA_CTLR_CHAN(0, 17))= , >> DMA_FILTER_ENTRY("spi_davinci.1", "rx", EDMA_CTLR_CHAN(0, 18= )), >> DMA_FILTER_ENTRY("spi_davinci.1", "tx", EDMA_CTLR_CHAN(0, 19= )), >> }; >=20 > I wonder if we should mandate that the lookup table is 'const'. I had been wondering the same, I'll make it const for the next round. > We could also drop the DMA_FILTER_ENTRY() macro above, and open-code = the > table like >=20 > static struct dma_filter_map da830_edma_map[] =3D { > { "davinci-mcasp.0", "rx", EDMA_CTLR_CHAN(0, 0)}, > { "davinci-mcasp.0", "tx", EDMA_CTLR_CHAN(0, 1)}, > { "davinci-mcasp.1", "rx", EDMA_CTLR_CHAN(0, 2)}, > ... > }; >=20 > which is a little more compact and more obvious, but loses the > named initializers. We would need: { "da830-mmc.0", "rx", (void*)EDMA_CTLR_CHAN(0, 16) }, { "da830-mmc.0", "tx", (void*)EDMA_CTLR_CHAN(0, 17) }, as we need to cast the param. It is still compact, but having to add the (void*) casting makes it a b= it ugly. --=20 P=E9ter -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html