From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Terje_Bergstr=F6m?= Subject: Re: [PATCH 1/2] clk: tegra114: Rename gr_2d/gr_3d to gr2d/gr3d Date: Tue, 8 Oct 2013 11:20:07 +0300 Message-ID: <5253C037.8070105@nvidia.com> References: <1380748361-32459-1-git-send-email-treding@nvidia.com> <524EF436.4000704@wwwdotorg.org> <20131007001433.7445.7915@quantum> <20131007142839.GC3973@tbergstrom-lnx.Nvidia.com> <20131007145343.GA19045@ulmo.nvidia.com> <20131008075356.GD3973@tbergstrom-lnx.Nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131008075356.GD3973-Rysk9IDjsxmJz7etNGeUX8VPkgjIgRvpAL8bYrjMMd8@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter De Schrijver , Thierry Reding Cc: Mike Turquette , Mark Zhang , Stephen Warren , Prashant Gaikwad , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 08.10.2013 10:53, Peter De Schrijver wrote: > On Mon, Oct 07, 2013 at 04:53:44PM +0200, Thierry Reding wrote: >> What's wrong with pll_c? We've used it for Tegra20 and Tegra30 and I >> have at least tested that gr2d works properly with it. It will also >> cause both host1x and gr2d to run off the same clock, which I guess may >> not matter at all. > Using pll_c2 is consistent with our policy in downstream. It allows more > freedom in scaling gr2d independently from host1x. host1x really should be on a clock that is not scaled. This is because it has some registers that need to be calibrated to the clock rate. It's a pain to recalibrate whenever clock rate is modified. This is why host1x is on PLLP downstream. 2D on the other hand (and all clients) is a prime candidate for clock scaling. This all is of course just hypothetical as long as we don't really scale host1x' or its clients' clocks. Terje