| Message ID | 1356084595-17800-1-git-send-email-linuxzsc@gmail.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
On 12/21/2012 03:09 AM, Richard Zhao wrote: > tegra_cpu_init/exit will be called every time one cpu core is online or > offline. And all cpu cores share same clocks, redundant clk_get/put > wast time, so I move them out. I think this is reasonable. Prashant, Peter, any comments? Is any other work in tegra_cpu_init() redundant? Is tegra_cpu_init() supposed to be called due to hotplug, or is that a bug in the cpufreq core? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Saturday 22 December 2012 02:57 AM, Stephen Warren wrote: > On 12/21/2012 03:09 AM, Richard Zhao wrote: >> tegra_cpu_init/exit will be called every time one cpu core is online or >> offline. And all cpu cores share same clocks, redundant clk_get/put >> wast time, so I move them out. > I think this is reasonable. > > Prashant, Peter, any comments? > > Is any other work in tegra_cpu_init() redundant? Is tegra_cpu_init() > supposed to be called due to hotplug, or is that a bug in the cpufreq core? Looks good. Also, instead of array we can use single variable for target_cpu_speed. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Dec 23, 2012 at 6:35 PM, Prashant Gaikwad <pgaikwad@nvidia.com> wrote: > On Saturday 22 December 2012 02:57 AM, Stephen Warren wrote: >> >> On 12/21/2012 03:09 AM, Richard Zhao wrote: >>> >>> tegra_cpu_init/exit will be called every time one cpu core is online or >>> offline. And all cpu cores share same clocks, redundant clk_get/put >>> wast time, so I move them out. >> >> I think this is reasonable. >> >> Prashant, Peter, any comments? >> >> Is any other work in tegra_cpu_init() redundant? Is tegra_cpu_init() >> supposed to be called due to hotplug, or is that a bug in the cpufreq >> core? When cpu goes offline, kernel don't know whether it'll come back. Sounds reasonable. > > > Looks good. Also, instead of array we can use single variable for > target_cpu_speed. I think yes. If one day the cores support rate changing independently, we can create another driver. It supposed to be another patch to do it. Thanks Richard -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Dec 23, 2012 at 11:35:26AM +0100, Prashant Gaikwad wrote: > On Saturday 22 December 2012 02:57 AM, Stephen Warren wrote: > > On 12/21/2012 03:09 AM, Richard Zhao wrote: > >> tegra_cpu_init/exit will be called every time one cpu core is online or > >> offline. And all cpu cores share same clocks, redundant clk_get/put > >> wast time, so I move them out. > > I think this is reasonable. > > > > Prashant, Peter, any comments? > > > > Is any other work in tegra_cpu_init() redundant? Is tegra_cpu_init() > > supposed to be called due to hotplug, or is that a bug in the cpufreq core? > > Looks good. Also, instead of array we can use single variable for > target_cpu_speed. > No. The target_cpu_speed becomes useful once we have clusterswitching. We can use it to determine if we want to switch to the other cluster. Cheers, Peter. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Dec 21, 2012 at 10:27:43PM +0100, Stephen Warren wrote: > On 12/21/2012 03:09 AM, Richard Zhao wrote: > > tegra_cpu_init/exit will be called every time one cpu core is online or > > offline. And all cpu cores share same clocks, redundant clk_get/put > > wast time, so I move them out. > > I think this is reasonable. > > Prashant, Peter, any comments? > > Is any other work in tegra_cpu_init() redundant? Is tegra_cpu_init() > supposed to be called due to hotplug, or is that a bug in the cpufreq core? I think we want to keep target_cpu_speed[] as a possible input for the (to be upstreamed) cluster switching logic. Yes, tegra_cpu_init() should be called due to hotplug. Some systems might need specific initialization for cpufreq when a new CPU comes online. Also the available frequencies might be different per CPU. So this information needs to be provided for each CPU. Cheers, Peter. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/21/2012 03:09 AM, Richard Zhao wrote: > tegra_cpu_init/exit will be called every time one cpu core is online or > offline. And all cpu cores share same clocks, redundant clk_get/put > wast time, so I move them out. I've applied this to Tegra's for-3.9/soc branch. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mach-tegra/cpu-tegra.c b/arch/arm/mach-tegra/cpu-tegra.c index 627bf0f..4faa3c6 100644 --- a/arch/arm/mach-tegra/cpu-tegra.c +++ b/arch/arm/mach-tegra/cpu-tegra.c @@ -217,24 +217,6 @@ static int tegra_cpu_init(struct cpufreq_policy *policy) if (policy->cpu >= NUM_CPUS) return -EINVAL; - cpu_clk = clk_get_sys(NULL, "cpu"); - if (IS_ERR(cpu_clk)) - return PTR_ERR(cpu_clk); - - pll_x_clk = clk_get_sys(NULL, "pll_x"); - if (IS_ERR(pll_x_clk)) - return PTR_ERR(pll_x_clk); - - pll_p_clk = clk_get_sys(NULL, "pll_p"); - if (IS_ERR(pll_p_clk)) - return PTR_ERR(pll_p_clk); - - emc_clk = clk_get_sys("cpu", "emc"); - if (IS_ERR(emc_clk)) { - clk_put(cpu_clk); - return PTR_ERR(emc_clk); - } - clk_prepare_enable(emc_clk); clk_prepare_enable(cpu_clk); @@ -259,8 +241,6 @@ static int tegra_cpu_exit(struct cpufreq_policy *policy) { cpufreq_frequency_table_cpuinfo(policy, freq_table); clk_disable_unprepare(emc_clk); - clk_put(emc_clk); - clk_put(cpu_clk); return 0; } @@ -281,12 +261,32 @@ static struct cpufreq_driver tegra_cpufreq_driver = { static int __init tegra_cpufreq_init(void) { + cpu_clk = clk_get_sys(NULL, "cpu"); + if (IS_ERR(cpu_clk)) + return PTR_ERR(cpu_clk); + + pll_x_clk = clk_get_sys(NULL, "pll_x"); + if (IS_ERR(pll_x_clk)) + return PTR_ERR(pll_x_clk); + + pll_p_clk = clk_get_sys(NULL, "pll_p"); + if (IS_ERR(pll_p_clk)) + return PTR_ERR(pll_p_clk); + + emc_clk = clk_get_sys("cpu", "emc"); + if (IS_ERR(emc_clk)) { + clk_put(cpu_clk); + return PTR_ERR(emc_clk); + } + return cpufreq_register_driver(&tegra_cpufreq_driver); } static void __exit tegra_cpufreq_exit(void) { cpufreq_unregister_driver(&tegra_cpufreq_driver); + clk_put(emc_clk); + clk_put(cpu_clk); }
tegra_cpu_init/exit will be called every time one cpu core is online or offline. And all cpu cores share same clocks, redundant clk_get/put wast time, so I move them out. Signed-off-by: Richard Zhao <linuxzsc@gmail.com> --- arch/arm/mach-tegra/cpu-tegra.c | 40 +++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-)