On Fri, 2018-08-31 at 06:12 +0000, Andy Tang wrote: > Hi Scott, > > Please see my replay inline. > > > -----Original Message----- > > From: linux-arm-kernel <linux-arm-kernel-bounces@xxxxxxxxxxxxxxxxxxx> > > On Behalf Of Scott Wood > > Sent: 2018年8月31日 1:43 > > To: Vabhav Sharma <vabhav.sharma@xxxxxxx>; > > linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > > robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; > > linuxppc-dev@xxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > > mturquette@xxxxxxxxxxxx; sboyd@xxxxxxxxxx; rjw@xxxxxxxxxxxxx; > > viresh.kumar@xxxxxxxxxx; linux-clk@xxxxxxxxxxxxxxx; > > linux-pm@xxxxxxxxxxxxxxx; linux-kernel-owner@xxxxxxxxxxxxxxx; > > catalin.marinas@xxxxxxx; will.deacon@xxxxxxx; > > gregkh@xxxxxxxxxxxxxxxxxxx; arnd@xxxxxxxx; > > kstewart@xxxxxxxxxxxxxxxxxxx; yamada.masahiro@xxxxxxxxxxxxx > > Cc: Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>; Andy Tang > > <andy.tang@xxxxxxx>; linux@xxxxxxxxxxxxxxx; Varun Sethi > > <V.Sethi@xxxxxxx>; Udit Kumar <udit.kumar@xxxxxxx> > > Subject: Re: [PATCH 3/5] drivers: clk-qoriq: Add clockgen support for > > lx2160a > > > > On Thu, 2018-08-30 at 12:39 -0500, Scott Wood wrote: > > > On Thu, 2018-08-30 at 07:36 +0000, Vabhav Sharma wrote: > > > > > > > > > > Why are you increasing NUM_CMUX beyond 8 for a chip that only > > > > has > > > > > 8 entries in cmux_to_group? > > > > > > > > Configuration is 16 cores,8 cluster with 2 cores in each cluster > > > > > > So? This is about cmuxes, not cores. You're increasing the array > > > without ever using the new size. > > > > Oh, and you also broke p4080 which has 8 cmuxes but no -1 terminator, > > because the array was of length 8. Probably the array should be changed > > to NUM_CMUX+1 so every array can be -1 terminated. > > > > [Andy] How about we add -1 terminator to p4080 and increase NUM_CMUX to 16? Why 16? What does such a change have to do with this chip, which according to the rest of the patch has 8 cmuxes? > We don't want to increase NUM_CMUX each time new soc with more cmuxes added. You don't want to have to make a trivial change each time you exceed a limit that has yet to be exceeded once since NUM_CMUX was added? This isn't ABI or in any other way hard to change. It's right in the same file as the chip description you'd be adding. And even if a chip did come along with 16 cmuxes, you'd then need to increase the array to 17 to hold the -1 if you don't want to leave a situation like the p4080 is in now, where a chip's cmux array could be broken by increasing NUM_CMUX further. -Scott
