From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Sat, 2 Aug 2014 21:06:15 +0200 Subject: [PATCH] Documentation: dmaengine: Add a documentation for the dma controller API In-Reply-To: <20140802151714.GB30282@n2100.arm.linux.org.uk> References: <1406736193-26685-1-git-send-email-maxime.ripard@free-electrons.com> <20140730160607.GM8181@intel.com> <20140731074440.GY3952@lukather> <20140731115628.GQ8181@intel.com> <20140731162330.GE3952@lukather> <20140801171306.GF8181@intel.com> <20140802144925.GJ3952@lukather> <20140802151714.GB30282@n2100.arm.linux.org.uk> Message-ID: <20140802190615.GO3952@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Aug 02, 2014 at 04:17:14PM +0100, Russell King - ARM Linux wrote: > On Sat, Aug 02, 2014 at 04:49:25PM +0200, Maxime Ripard wrote: > > In the case of the call to device_control, especially in the > > DMA_SLAVE_CONFIG case, but that also applies to pause/resume, are the > > changes supposed to be immediates or can they happen later? > > pause/resume are expected to operate synchronously on the channel. > When asking for the channel to pause, the channel must be stopped > before the call returns. > > In the case of channel configuration, that should have no effect on > any previously queued transfer - in other words, changing the channel > configuration only has an effect when subsequent transactions are > prepared. Ok, thanks! -- 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: