Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758468AbbFBJUZ (ORCPT ); Tue, 2 Jun 2015 05:20:25 -0400 Received: from down.free-electrons.com ([37.187.137.238]:51773 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752501AbbFBJUF (ORCPT ); Tue, 2 Jun 2015 05:20:05 -0400 Date: Tue, 2 Jun 2015 11:19:51 +0200 From: Maxime Ripard To: Vinod Koul , dmaengine@vger.kernel.org, Nicolas Ferre , Alexandre Belloni , Thomas Petazzoni , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/2] dmaengine: hdmac: Implement interleaved transfers Message-ID: <20150602091951.GV23777@lukather> References: <1432735313-481-1-git-send-email-maxime.ripard@free-electrons.com> <1432735313-481-3-git-send-email-maxime.ripard@free-electrons.com> <20150601083216.GH25118@odux.rfo.atmel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="5FFaGRZUwcpbKFrw" Content-Disposition: inline In-Reply-To: <20150601083216.GH25118@odux.rfo.atmel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2173 Lines: 61 --5FFaGRZUwcpbKFrw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Mon, Jun 01, 2015 at 10:32:16AM +0200, Ludovic Desroches wrote: > > channel_writel(atchan, CTRLA, 0); > > channel_writel(atchan, CTRLB, 0); > > channel_writel(atchan, DSCR, first->txd.phys); > > + channel_writel(atchan, SPIP, ATC_SPIP_HOLE(first->src_hole) | > > + ATC_SPIP_BOUNDARY(first->boundary)); > > + channel_writel(atchan, DPIP, ATC_DPIP_HOLE(first->dst_hole) | > > + ATC_DPIP_BOUNDARY(first->boundary)); >=20 > Can't we get a trivial condition to perform these two writes only if > needed? Is that really needed? My understanding is that the hardware will only take this into account if we set the ATC_SRC_PIP and ATC_DST_PIP bits anyway, so the check is already there. Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --5FFaGRZUwcpbKFrw Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVbXU3AAoJEBx+YmzsjxAgWQQP/00vrn2EcISsQYMsQYoTla1i TUFt3qXXHeQzjKI4dIzV8XopQryUR7ll8KqWPQFw0Ee/zHapxd5a6nKH5btaT4M8 PdnBLKyv9nnEjJPPywwmIsME9ZWfL/Lsk49D0jL7voGM4Fnjv6mZCed/rA5Wg5NR u/iOqYJE0CaL9SOdvg8hVYGaoy+HWRKQsjCAVdPMBTIq5jxSA4p3iJisbMYiJtrh BDx54zUDm9KKmTV5PDjrhCMX0oEQO//INAjJopqNOFI0SoOPAQuitjvfeC4TP5WE X5CIp0ZO5Wf7mTbQTrMH/jO6Ex8/wj7z2YAUoTR7HmTeJy2ZRJw1hg0/n3hPSsD0 oaBIs3VeKObS/ajmeuEWjMb3bUJVK3t2vBVkPGl1xXPRe+gak4OOk5UDJN+WPmeX pnO7tsebWLCaXlNPbWCitDG51zZZFhKpOSQ4raBeTg/3ylXUxnaLNvz6GlfPGZKV fPd2GTXKqxjb83yGqys3kLQK1EMM85akeSETvJx6J7FwJhYKN9uBqJdHsdMz6rc+ sG/QutMC0aquZ1j3AssgTOHGO8DBwIXriLxC+2DGz/rkNU6VqhVCsyKVnfBHbzL/ rUyz/YOEp/HBVJNO1iSbcYgegqWyp5fS52tMhj18RMY5EsfH7pTnAUyO8zGqCMa7 zNJIKP3skFHIuVzdKhdH =ldoy -----END PGP SIGNATURE----- --5FFaGRZUwcpbKFrw-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/