| Message ID | 1425914206-22295-2-git-send-email-lina.iyer@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Mon, Mar 09 2015 at 15:29 -0600, Andy Gross wrote: >On Mon, Mar 09, 2015 at 09:16:36AM -0600, Lina Iyer wrote: >> From: Daniel Lezcano <daniel.lezcano@linaro.org> >> >> Some architectures have some cpus which does not support idle states. >> >> Let the underlying low level code to return -ENOSYS when it is not >> possible to set an idle state. >> >> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> >> Signed-off-by: Lina Iyer <lina.iyer@linaro.org> >> [Minor clean ups and fixes of the per-cpu variable] >> --- >> drivers/cpuidle/cpuidle-arm.c | 34 +++++++++++++++++++++++++++++++++- >> 1 file changed, 33 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c >> index 1c94b88..f7cdb73 100644 >> --- a/drivers/cpuidle/cpuidle-arm.c >> +++ b/drivers/cpuidle/cpuidle-arm.c >> @@ -17,11 +17,14 @@ >> #include <linux/kernel.h> >> #include <linux/module.h> >> #include <linux/of.h> >> +#include <linux/slab.h> >> >> #include <asm/cpuidle.h> >> >> #include "dt_idle_states.h" >> >> +static DEFINE_PER_CPU(struct cpuidle_device, *cpuidle_arm_dev); >> + >> /* >> * arm_enter_idle_state - Programs CPU to enter the specified state >> * >> @@ -93,6 +96,7 @@ static const struct of_device_id arm_idle_state_match[] __initconst = { >> static int __init arm_idle_init(void) >> { >> int cpu, ret; >> + struct cpuidle_device *dev; >> struct cpuidle_driver *drv = &arm_idle_driver; >> >> /* >> @@ -105,18 +109,46 @@ static int __init arm_idle_init(void) >> if (ret <= 0) >> return ret ? : -ENODEV; >> >> + >> + ret = cpuidle_register_driver(drv); >> + if (ret) { >> + pr_err("Failed to register cpuidle driver\n"); >> + return ret; >> + } >> + >> /* >> * Call arch CPU operations in order to initialize >> * idle states suspend back-end specific data >> */ >> for_each_possible_cpu(cpu) { >> + >> ret = arm_cpuidle_init(cpu); >> + /* >> + * This cpu does not support any idle states >> + */ >> + if (ret == -ENOSYS) >> + continue; >> + >> if (ret) { >> pr_err("CPU %d failed to init idle CPU ops\n", cpu); >> return ret; >> } >> + >> + dev = kzalloc(sizeof(*dev), GFP_KERNEL); > >devm_kzalloc? Otherwise, failures could lead to lost memory. > I dont have a local device to work with for allocation. May be I can get the cpu device node and the device therefore for allocation. Thoughts? >> + if (!dev) >> + return -ENOMEM; >> + >> + dev->cpu = cpu; >> + ret = cpuidle_register_device(dev); >> + if (ret) { >> + pr_err("Failed to register cpuidle device for CPU %d\n", >> + cpu); >> + return ret; >> + } >> + >> + per_cpu(cpuidle_arm_dev, cpu) = dev; >> } >> >> - return cpuidle_register(drv, NULL); >> + return 0; >> } >> device_initcall(arm_idle_init); >> -- >> 2.1.0 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > >-- >Qualcomm Innovation Center, Inc. >The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, >a Linux Foundation Collaborative Project > -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Mar 10 2015 at 04:37 -0600, Russell King - ARM Linux wrote: >On Mon, Mar 09, 2015 at 09:16:36AM -0600, Lina Iyer wrote: >> @@ -105,18 +109,46 @@ static int __init arm_idle_init(void) >> if (ret <= 0) >> return ret ? : -ENODEV; >> >> + > >A bit better formatting would be nice - you don't need the extra blank >line here. > >> + ret = cpuidle_register_driver(drv); >> + if (ret) { >> + pr_err("Failed to register cpuidle driver\n"); >> + return ret; >> + } >> + >> /* >> * Call arch CPU operations in order to initialize >> * idle states suspend back-end specific data >> */ >> for_each_possible_cpu(cpu) { >> + > >This blank line is not necessary either. > >> ret = arm_cpuidle_init(cpu); > >However, a blank line here would be a good thing. > Sure. >> + /* >> + * This cpu does not support any idle states >> + */ > >Also, formatting this as /* This cpu does not support any idle states */ is >acceptable too, and doesn't waste as many lines. > Will fix. >> + if (ret == -ENOSYS) >> + continue; >> + >> if (ret) { >> pr_err("CPU %d failed to init idle CPU ops\n", cpu); >> return ret; >> } >> + >> + dev = kzalloc(sizeof(*dev), GFP_KERNEL); >> + if (!dev) >> + return -ENOMEM; >> + >> + dev->cpu = cpu; >> + ret = cpuidle_register_device(dev); >> + if (ret) { >> + pr_err("Failed to register cpuidle device for CPU %d\n", >> + cpu); >> + return ret; > >It looks like we leak the 'dev' allocation here. > True, I will amend that. >Also, other error paths, it looks like we leave the previously registered >cpuidle devices in place. That may be acceptable if the intention is to >initialise as many CPUs as possible - but we then miss the >cpuidle_register() call below, which seems to make the registered devices >useless. It's a little inconsistent. > >Also, it's useful to report why something fails - printing the error code >can help debugging if it isn't already printed elsewhere. > Fair point. >> + } >> + >> + per_cpu(cpuidle_arm_dev, cpu) = dev; >> } >> >> - return cpuidle_register(drv, NULL); >> + return 0; >> } >> device_initcall(arm_idle_init); > >-- >FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up >according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" 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/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c index 1c94b88..f7cdb73 100644 --- a/drivers/cpuidle/cpuidle-arm.c +++ b/drivers/cpuidle/cpuidle-arm.c @@ -17,11 +17,14 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/slab.h> #include <asm/cpuidle.h> #include "dt_idle_states.h" +static DEFINE_PER_CPU(struct cpuidle_device, *cpuidle_arm_dev); + /* * arm_enter_idle_state - Programs CPU to enter the specified state * @@ -93,6 +96,7 @@ static const struct of_device_id arm_idle_state_match[] __initconst = { static int __init arm_idle_init(void) { int cpu, ret; + struct cpuidle_device *dev; struct cpuidle_driver *drv = &arm_idle_driver; /* @@ -105,18 +109,46 @@ static int __init arm_idle_init(void) if (ret <= 0) return ret ? : -ENODEV; + + ret = cpuidle_register_driver(drv); + if (ret) { + pr_err("Failed to register cpuidle driver\n"); + return ret; + } + /* * Call arch CPU operations in order to initialize * idle states suspend back-end specific data */ for_each_possible_cpu(cpu) { + ret = arm_cpuidle_init(cpu); + /* + * This cpu does not support any idle states + */ + if (ret == -ENOSYS) + continue; + if (ret) { pr_err("CPU %d failed to init idle CPU ops\n", cpu); return ret; } + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + dev->cpu = cpu; + ret = cpuidle_register_device(dev); + if (ret) { + pr_err("Failed to register cpuidle device for CPU %d\n", + cpu); + return ret; + } + + per_cpu(cpuidle_arm_dev, cpu) = dev; } - return cpuidle_register(drv, NULL); + return 0; } device_initcall(arm_idle_init);