From mboxrd@z Thu Jan 1 00:00:00 1970 From: sricharan@codeaurora.org (Sricharan) Date: Fri, 24 Jul 2015 17:56:10 +0530 Subject: [RFC PATCH 3/4] iommu/arm-smmu: Add support for specifying clocks In-Reply-To: <20150721150122.GH31095@arm.com> References: <1437152005-25092-1-git-send-email-sricharan@codeaurora.org> <1437152005-25092-4-git-send-email-sricharan@codeaurora.org> <20150721150122.GH31095@arm.com> Message-ID: <005e01d0c60b$f1f130c0$d5d39240$@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Will, > -----Original Message----- > From: linux-arm-msm-owner at vger.kernel.org [mailto:linux-arm-msm- > owner at vger.kernel.org] On Behalf Of Will Deacon > Sent: Tuesday, July 21, 2015 8:31 PM > To: Sricharan R > Cc: linux-arm-kernel at lists.infradead.org; iommu at lists.linux-foundation.org; > devicetree at vger.kernel.org; linux-arm-msm at vger.kernel.org; > mitchelh at codeaurora.org > Subject: Re: [RFC PATCH 3/4] iommu/arm-smmu: Add support for specifying > clocks > > On Fri, Jul 17, 2015 at 05:53:24PM +0100, Sricharan R wrote: > > From: Mitchel Humpherys > > > > On some platforms with tight power constraints it is polite to only > > leave your clocks on for as long as you absolutely need them. > > Currently we assume that all clocks necessary for SMMU register access > > are always on. > > You've borrowed this commit message from Mitch's previous version of this > patch, but now you leave the clocks enabled most of the time so it doesn't > make much sense anymore. > Sorry, I should have changed that to make it clear. > Anyway, I'm OK with this kind of clock management in the driver, but I think > that anything more fine-grained needs to be designed into the IOMMU core. > Ok. Tried this to get the right direction. I will check for the power savings and if there are not much then I would use the above approach. Regards, Sricharan