From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH resend 1/2] clk: tegra: remove USB from clk init table Date: Wed, 17 Apr 2013 09:10:52 -0600 Message-ID: <516EBB7C.5050903@wwwdotorg.org> References: <1366011105-2351-1-git-send-email-dev@lynxeye.de> <516C3D3A.7000508@wwwdotorg.org> <516E9222.4080506@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <516E9222.4080506-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Prashant Gaikwad Cc: Peter De Schrijver , Lucas Stach , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 04/17/2013 06:14 AM, Prashant Gaikwad wrote: > On Monday 15 April 2013 11:17 PM, Stephen Warren wrote: >> On 04/15/2013 01:31 AM, Lucas Stach wrote: >>> The USB clocks are just clock gates, so no need to set a specific clock. >>> In fact trying to set a specific clock is just a NOP if the requested >>> clockrate is the same as those of the parent (clk_m) or will trigger a >>> WARN_ON() if rates don't match up. >>> >>> As we are not setting a specific rate, nor activating the clocks at >>> init, there is no point in keeping the the usb entries in the clock init >>> table. >> Peter, Prashant, I'd like to confirm that the usb* clocks really do have >> clk_m as their parent; we're sure they aren't driven by the 12MHz PLL_U >> output? >> >> Either way, I guess it's safe to take this patch since the clock would >> be fixed rate; I'd just like to make sure the clock driver is accurate. > > These are controller clocks and are not driven by PLL_U. So just to confirm: does that mean that they truly /are/ direct children of clk_m, just like the driver says right now?