From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [RFC/PATCH 3/3] omap3-iommu: remote registration Date: Mon, 18 May 2009 14:02:33 +0100 Message-ID: <20090518130233.GD3067@n2100.arm.linux.org.uk> References: <1242468350-23190-1-git-send-email-felipe.contreras@gmail.com> <1242468350-23190-2-git-send-email-felipe.contreras@gmail.com> <1242468350-23190-3-git-send-email-felipe.contreras@gmail.com> <1242468350-23190-4-git-send-email-felipe.contreras@gmail.com> <20090518121113.GB3067@n2100.arm.linux.org.uk> <94a0d4530905180546p47c887afj109b3b60cdd24a00@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:56382 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751665AbZERNCp (ORCPT ); Mon, 18 May 2009 09:02:45 -0400 Content-Disposition: inline In-Reply-To: <94a0d4530905180546p47c887afj109b3b60cdd24a00@mail.gmail.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Felipe Contreras Cc: linux-omap@vger.kernel.org, Hiroshi DOYU , Hari Kanigeri , linux-arm-kernel@lists.arm.linux.org.uk On Mon, May 18, 2009 at 03:46:07PM +0300, Felipe Contreras wrote: > On Mon, May 18, 2009 at 3:11 PM, Russell King - ARM Linux > wrote: > > The real problem here seems to be the TI DSP bridge code, and if th= at's > > the case why can't we just avoid registering IVA2 if the TI DSP bri= dge > > code is enabled. =A0That solves your stated problem without creatin= g > > additional management issues. >=20 > The bridgedriver is expected to move and use iommu eventually, but no= t > right now, so I guess the iva2 device should be registered only if > MPU_BRIDGE_IOMMU is defined. >=20 > But then what's the point of having the isp iommu device if the camer= a > driver is disabled? Wouldn't that be wasting resources? Then if CAMER= A > is not defined the isp device should not be registered either. So have something like: config OMAP_IOMMU tristate and then have both MPU_BRIDGE_IOMMU and the camera support (and whateve= r else) select it. That way, you only end up with the IOMMU support code built into the kernel if you have users of it. These low-level internal services drivers really don't need to be publically visible in the configuration system. As for the run-time size, that's truely minimal. > And finally if none of the two are enabled then you don't really > iommu. By having omap_iommu_add all the dependencies would be handled > automatically, right? 'modprobe bridgedriver' would load iommu. Think about it - the dependencies _already_ have to be there to use the iommu services. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html