From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: Depreciated spi_master.transfer and "prepared spi messages" for an optimized pipelined-SPI-DMA-driver Date: Wed, 13 Nov 2013 15:11:02 +0000 Message-ID: <20131113151102.GS878@sirena.org.uk> References: <20131107203127.GB2493@sirena.org.uk> <86AE15B6-05AF-4EFF-8B8F-10806A7C148B@sperl.org> <20131108161957.GP2493@sirena.org.uk> <5F70E708-89B9-4DCF-A31A-E688BAA0E062@sperl.org> <20131108180934.GQ2493@sirena.org.uk> <20131109183056.GU2493@sirena.org.uk> <6C7903B3-8563-490E-AD7D-BA5D65FFB9BC@sperl.org> <20131112011954.GH2674@sirena.org.uk> <52823E73.503@sperl.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="p2u4WfPhYOuYlOsk" Cc: linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Martin Sperl Return-path: Content-Disposition: inline In-Reply-To: <52823E73.503-d5rIkyn9cnPYtjvyW6yDsg@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: --p2u4WfPhYOuYlOsk Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Nov 12, 2013 at 03:42:59PM +0100, Martin Sperl wrote: Not fully read this yet but one thing... > >The messages and transfers ought to be totally reusable already, the > >only bit that should need to be recreated is any data the driver creates > >internally, most likely that's only going to be data for DMA. We do > >already have an interface for drivers to do the DMA mapping though it's > >not very well loved at the minute... > What DMA-interface are you talking about? at least in spi.h in 3.10 > I find nothing that would indicate an extra DMA interface... Drivers can supply pre-mapped DMA buffers if they set is_dma_mapped which is about as good as you get with dmaengine at the minute. The main opportunities for enhancement here are in the master interface rather than the client, at least as things stand. --p2u4WfPhYOuYlOsk Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJSg5aCAAoJELSic+t+oim9oO0P/jSkEI+OpxVY9jyZlsggiLVh 9HS2xPJvhSrmjLNN10SgDwDKrPGcr0mxtvw4gvImT9p7wHxFEUUv88uCxni/0X/C XTFqaz+qdnd3QkRtu6FARaVisAf7K5SoVGRHdmr71c0IjeW3Qf3kLC4j0y/cHMSm Yj2yawk0SVOoKlvX/uf6HfKnLdoUD8FI/PMm6d+nD0mmkM+URzvHNgNjJHDUuOxG xSIQKM6r3lpbFbqbqlPrIKXJxtGap2ItvfqThc9TTlyGKAnjiG80wVTpveGOsGSk wN6vIEaq+Gm5lFglpgMQMhn0cZNURyPYLEuZUdGbvHG2W9FEdpbDn5CYJExt/71x jaorHeXrf9ocdy+jPWt6acqH5/7EkWXiYRE7amWhY+SKMHQ/hpHmBDNtEm4NBqWT n3D6NI1aPQjjdR5sG5QwHjDDNnSVQMHn/5PpShzk70/+2PpvYYzcomI5zdYLR6dg mzzLOdx3nYyyxX+i8uCusrkEwKsw5S2mdsjdBDq9z7g09Jwa/08p3p48Zb8n6Nkb zPTdPnPSdkvgZnZdkXZFEU50at4aLdARN4rFf/FNCUAZJi5ZNthRFraZ17YR0hUr QSpkGfg7B1yad/0asyo0R9QUgn5e9tpxlkERhMZLJ85TPCpKfNVJklvFxeaatL84 ed/5RX/QDhR/Fdu3oDVj =N5Cn -----END PGP SIGNATURE----- --p2u4WfPhYOuYlOsk-- -- 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