From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Tue, 2 Jun 2015 11:19:51 +0200 Subject: [PATCH 2/2] dmaengine: hdmac: Implement interleaved transfers In-Reply-To: <20150601083216.GH25118@odux.rfo.atmel.com> 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> Message-ID: <20150602091951.GV23777@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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)); > > 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 -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: