From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Wed, 7 Oct 2015 12:04:57 +0100 Subject: [PATCH v3 1/5] clk: Add a basic multiplier clock In-Reply-To: <20151005180929.GB12338@codeaurora.org> References: <1443512353-28073-1-git-send-email-maxime.ripard@free-electrons.com> <1443512353-28073-2-git-send-email-maxime.ripard@free-electrons.com> <20151002204308.GY12338@codeaurora.org> <20151005101932.GH2696@lukather> <20151005180929.GB12338@codeaurora.org> Message-ID: <20151007110457.GF2278@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Oct 05, 2015 at 11:09:29AM -0700, Stephen Boyd wrote: > On 10/05, Maxime Ripard wrote: > > Hi, > > > > On Fri, Oct 02, 2015 at 01:43:08PM -0700, Stephen Boyd wrote: > > > On 09/29, Maxime Ripard wrote: > > > > + > > > > + if (!val && mult->flags & CLK_MULTIPLIER_ZERO_BYPASS) > > > > + val = 1; > > > > + > > > > + return parent_rate * val; > > > > +} > > > > + > > > > +static bool __is_best_rate(unsigned long rate, unsigned long new, > > > > + unsigned long best, unsigned long flags) > > > > +{ > > > > + if (flags & CLK_MULTIPLIER_ROUND_CLOSEST) > > > > > > Is the only difference in this function vs the divider one that > > > flag? Maybe we should make this function generic to the framework > > > and pass a flag indicating closest or not. > > > > Actually, the logic is also reversed. > > > > The divider driver will always try to find some rate that is higher > > than the one we already have, without going above than the one > > requested. > > > > Here, we're tring to be lower than the best rate, without going below > > the requested rate. > > So then a tri-state flag that indicates, closest, less than, > greater than? Still, the computation itself is different, and the only consolidation we could possibly do is by not duplicating the ROUND_CLOSEST. We would end up with two different code pathes in the same function, which I feel would make it unnecessarily complex. > > > > > > > > > > + unsigned long val; > > > > + > > > > + if (mult->lock) > > > > + spin_lock_irqsave(mult->lock, flags); > > > > > > This needs the same "trick" that we did in the generic clock > > > types to avoid sparse warnings. > > > > The __acquire call ? > > Yes. Ok. Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: