From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [RFC PATCH 6/6] spi: spi-s3c64xx: Move DMA initialization Date: Mon, 9 Sep 2013 15:53:51 +0100 Message-ID: <20130909145351.GD29403@sirena.org.uk> References: <1378735766-12330-1-git-send-email-l.czerwinski@samsung.com> <1378735766-12330-7-git-send-email-l.czerwinski@samsung.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="aSMWOr4h/ZU3vZ/E" Return-path: Received: from cassiel.sirena.org.uk ([80.68.93.111]:54945 "EHLO cassiel.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752415Ab3IIOyQ (ORCPT ); Mon, 9 Sep 2013 10:54:16 -0400 Content-Disposition: inline In-Reply-To: <1378735766-12330-7-git-send-email-l.czerwinski@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Lukasz Czerwinski Cc: s.nawrocki@samsung.com, linux-samsung-soc@vger.kernel.org, linux-spi@vger.kernel.org --aSMWOr4h/ZU3vZ/E Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Sep 09, 2013 at 04:09:26PM +0200, Lukasz Czerwinski wrote: > This patch removes DMA channel initialization and deinitialization for each > transfer. Now DMA channel is requested only at the driver initialization > and stored in driver data. So, this is fine but I had been under the impression that one of the reasons that the channels were only being requested at transfer time was that they could be used for other purposes too. If that is not the case then fine, if that is the case then probably moving to prepare/unprepare transfer hardware (when the clocks are enabled) would make more sense - that'd avoid repeated allocations and frees while the controller is busy which should be the main issue performance wise. --aSMWOr4h/ZU3vZ/E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.21 (GNU/Linux) iQIcBAEBAgAGBQJSLeD8AAoJELSic+t+oim9nNUP/3Pq7JSZ3ffa2eO3KyHSSiJl 1+qXiPNMv4px5dwJTdiR4W31dPBanbuVfYB1WGLlPToN7eYpVFpN12o2xd8Hh+3u Y5ssYJCB9TSdOQQv0ceuPFtK1rWVWUeyFMrcmqM6aA7PAy0ei+pANPdYij3IBxtX Ul+u2mFBQcZqDs76MMtxS0MRHDz3qvsen7U9Lvzv7kXZwJY5E6qMaj7t8jF1294D DQDozIMPAtViKkc8HOwYa1BSLNdndWdZHd3eExTUBBcfcaoDFGmg4BO54xA1DMvj A/y6VIFhyc9Y9BVWLYMLlWnN04VwbqUl7y5J461znla51iVFHc4ejTeZooEODcJ7 l0pALiaNhCBDsgWY8W8lSYYMrW5fCgv1KcHy2zXu8xCGQ3XsOGyyyojd48WC1+o+ eiM6UFweL0wgn/qjtmqDQXNHBbh9lNTOim6IT+SJtBWC2DlbHOaFFAHE3GHhVYFV LWjxu4ZeO4xGkAjSla1UnMaf2sHmO2KdUbyoTmIPbDh2w4pLwZ8L+yI32ghoEu42 nCgKYc+aEm3vmKR2v2srx+7J5x0thdLD8QEIOji9CdsXvub4KL1DAeLRJvoA0l8u MYku6LRDjMDsrjMyVVS9+vwebkmFYauXIkCjtQqd2Q/nYdDrqus02SUVPMVuKJeH r8ec3X2vWu0eIh4SFE3A =RIXS -----END PGP SIGNATURE----- --aSMWOr4h/ZU3vZ/E--