There are 2 CPU clusters in the Kryo, CPU 0 and 1 are called Silver Cluster and CPU 2 and 3 - Gold Cluster. Each cluster has single clock. The clusters differ in terms of speed capabilities, computing power and power consumption. Therefore, I define separate OPP table for each cluster, and my driver will choose the appropriate OPP subset for each cluster. Lead refers to first CPU in the cluster.
> -----Original Message----- > From: Russell King - ARM Linux <li...@armlinux.org.uk> > Sent: Monday, May 21, 2018 15:12 > To: ilia...@codeaurora.org > Cc: viresh.ku...@linaro.org; devicet...@vger.kernel.org; linux- > p...@vger.kernel.org; linux-arm-...@vger.kernel.org; linux- > ker...@vger.kernel.org; linux-...@vger.kernel.org; linux- > c...@vger.kernel.org; linux-arm-ker...@lists.infradead.org > Subject: Re: [PATCH] cpufreq: Add Kryo CPU scaling driver > > On Mon, May 21, 2018 at 02:05:41PM +0300, ilia...@codeaurora.org wrote: > > You are right. > > cpu_dev_silver != cpu_dev_gold, and I found this with my tests as well. > > Thank you. > > > > > -----Original Message----- > > > From: Russell King - ARM Linux <li...@armlinux.org.uk> > > > Sent: Monday, May 21, 2018 13:54 > > > To: Ilia Lin <ilia...@codeaurora.org> > > > Cc: viresh.ku...@linaro.org; devicet...@vger.kernel.org; linux- > > > p...@vger.kernel.org; linux-arm-...@vger.kernel.org; linux- > > > ker...@vger.kernel.org; linux-...@vger.kernel.org; linux- > > > c...@vger.kernel.org; linux-arm-ker...@lists.infradead.org > > > Subject: Re: [PATCH] cpufreq: Add Kryo CPU scaling driver > > > > > > On Mon, May 21, 2018 at 01:31:30PM +0300, Ilia Lin wrote: > > > > +#define SILVER_LEAD 0 > > > > +#define GOLD_LEAD 2 > > > > > > Okay, two different values here, but "GOLD_LEAD" appears unused. > > > > > > > + cpu_dev_silver = get_cpu_device(SILVER_LEAD); > > > > + if (NULL == cpu_dev_silver) > > > > + return -ENODEV; > > > > + > > > > + cpu_dev_gold = get_cpu_device(SILVER_LEAD); > > > > + if (NULL == cpu_dev_gold) > > > > + return -ENODEV; > > > > > > get_cpu_device() takes the logical CPU number. So the above gets > > > CPU 0 each time, and so cpu_dev_silver == cpu_dev_gold here. So > > > what's the point of the second get_cpu_device() ? If it's supposed to be: > > > > > > cpu_dev_gold = get_cpu_device(GOLD_LEAD); > > > > > > That would get CPU 2, but in terms of these defines, it doesn't make > > > that much sense. What exactly does "silver lead" and "gold lead" > > > refer to in > > these > > > definitions? > > I think you still need to explain this. > > -- > RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ > FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps > up According to speedtest.net: 8.21Mbps down 510kbps up
