From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subject: RE: [PATCH] cpufreq: Add Kryo CPU scaling driver Date: Mon, 21 May 2018 14:05:41 +0300 Message-ID: <000b01d3f0f3$aa961cc0$ffc25640$@codeaurora.org> References: <1526555955-29960-11-git-send-email-ilialin@codeaurora.org> <1526898690-4018-1-git-send-email-ilialin@codeaurora.org> <20180521105428.GM17671@n2100.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180521105428.GM17671@n2100.armlinux.org.uk> Content-Language: en-us Sender: linux-kernel-owner@vger.kernel.org To: 'Russell King - ARM Linux' Cc: viresh.kumar@linaro.org, devicetree@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-soc@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org 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 > Sent: Monday, May 21, 2018 13:54 > To: Ilia Lin > Cc: viresh.kumar@linaro.org; devicetree@vger.kernel.org; linux- > pm@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux- > kernel@vger.kernel.org; linux-soc@vger.kernel.org; linux- > clk@vger.kernel.org; linux-arm-kernel@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? > > > + opp_silver = > dev_pm_opp_set_supported_hw(cpu_dev_silver,&versions,1); > > + if (IS_ERR(opp_silver)) { > > + dev_err(cpu_dev_silver, "Failed to set supported > hardware\n"); > > + ret = PTR_ERR(opp_silver); > > + goto free_np; > > + } > > + > > + opp_gold = > dev_pm_opp_set_supported_hw(cpu_dev_gold,&versions,1); > > + if (IS_ERR(opp_gold)) { > > + dev_err(cpu_dev_gold, "Failed to set supported > hardware\n"); > > + ret = PTR_ERR(opp_gold); > > + goto free_opp_silver; > > + } > > Given that cpu_dev_silver == cpu_dev_gold, doesn't the second call to > dev_pm_opp_set_supported_hw() always fail, as opp_table- > >supported_hw will be set by the first call? > > To me, this driver looks completely useless as it will always fail to initialise, > and I question whether this code has even been runtime tested. > > -- > 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