| Message ID | 1418125716-18528-1-git-send-email-k.kozlowski@samsung.com |
|---|---|
| State | New |
| Headers | show |
On Tuesday 09 December 2014 12:48:36 Krzysztof Kozlowski wrote: > Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by > disabling SUSPEND) and CPU_IDLE enabled: > > arch/arm64/kernel/psci.c:543:2: error: unknown field ‘cpu_suspend’ specified in initializer > .cpu_suspend = cpu_psci_cpu_suspend, > ^ > arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default] > arch/arm64/kernel/psci.c:543:2: warning: (near initialization for ‘cpu_psci_ops.cpu_prepare’) [enabled by default] > make[1]: *** [arch/arm64/kernel/psci.o] Error 1 > > The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is > defined, not CPU_IDLE. > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > No objection to fixing this obvious build bug, but why do we even have an ARM64_CPU_SUSPEND option? On ARM32 we only have the respective option because we have a random collection of platform specific drivers that use the symbols, but that's not the case on ARM64. Arnd
On wto, 2014-12-09 at 13:29 +0100, Arnd Bergmann wrote: > On Tuesday 09 December 2014 12:48:36 Krzysztof Kozlowski wrote: > > Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by > > disabling SUSPEND) and CPU_IDLE enabled: > > > > arch/arm64/kernel/psci.c:543:2: error: unknown field ‘cpu_suspend’ specified in initializer > > .cpu_suspend = cpu_psci_cpu_suspend, > > ^ > > arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default] > > arch/arm64/kernel/psci.c:543:2: warning: (near initialization for ‘cpu_psci_ops.cpu_prepare’) [enabled by default] > > make[1]: *** [arch/arm64/kernel/psci.o] Error 1 > > > > The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is > > defined, not CPU_IDLE. > > > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > > > No objection to fixing this obvious build bug, but why do we even have > an ARM64_CPU_SUSPEND option? On ARM32 we only have the respective option > because we have a random collection of platform specific drivers that > use the symbols, but that's not the case on ARM64. I believe because of cpuidle. It's the same as on ARM32: the cpu_suspend is used by both PM_SLEEP and CPU_IDLE. Best regards, Krzysztof
On Tue, Dec 09, 2014 at 12:38:09PM +0000, Krzysztof Kozlowski wrote: > On wto, 2014-12-09 at 13:29 +0100, Arnd Bergmann wrote: > > On Tuesday 09 December 2014 12:48:36 Krzysztof Kozlowski wrote: > > > Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by > > > disabling SUSPEND) and CPU_IDLE enabled: > > > > > > arch/arm64/kernel/psci.c:543:2: error: unknown field ‘cpu_suspend’ specified in initializer > > > .cpu_suspend = cpu_psci_cpu_suspend, > > > ^ > > > arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default] > > > arch/arm64/kernel/psci.c:543:2: warning: (near initialization for ‘cpu_psci_ops.cpu_prepare’) [enabled by default] > > > make[1]: *** [arch/arm64/kernel/psci.o] Error 1 > > > > > > The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is > > > defined, not CPU_IDLE. > > > > > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > > > > > > No objection to fixing this obvious build bug, but why do we even have > > an ARM64_CPU_SUSPEND option? On ARM32 we only have the respective option > > because we have a random collection of platform specific drivers that > > use the symbols, but that's not the case on ARM64. > > I believe because of cpuidle. It's the same as on ARM32: the cpu_suspend > is used by both PM_SLEEP and CPU_IDLE. I guess at some point we can replace (as a separate patch) ARM64_CPU_SUSPEND with PM_SLEEP. But what I don't fully understand, we can enable CPU_IDLE without ARM64_CPU_SUSPEND. However, the cpuidle-arm64.c driver will fail to link since it calls cpu_suspend(). Wouldn't it be better if ARM64_CPU_SUSPEND depends on CPU_PM (or replaced by it) rather than PM_SLEEP? Can we allow deeper idle states when CONFIG_SUSPEND is disabled? I see CONFIG_SUSPEND related to suspend-to-RAM (system standby) rather than CPU idle, in which case we may want to allow cpu_suspend when only CPU_IDLE is enabled (which implies CONFIG_CPU_PM).
On Tue, Dec 09, 2014 at 04:15:11PM +0000, Catalin Marinas wrote: > On Tue, Dec 09, 2014 at 12:38:09PM +0000, Krzysztof Kozlowski wrote: > > On wto, 2014-12-09 at 13:29 +0100, Arnd Bergmann wrote: > > > On Tuesday 09 December 2014 12:48:36 Krzysztof Kozlowski wrote: > > > > Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by > > > > disabling SUSPEND) and CPU_IDLE enabled: > > > > > > > > arch/arm64/kernel/psci.c:543:2: error: unknown field 'cpu_suspend' specified in initializer > > > > .cpu_suspend = cpu_psci_cpu_suspend, > > > > ^ > > > > arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default] > > > > arch/arm64/kernel/psci.c:543:2: warning: (near initialization for 'cpu_psci_ops.cpu_prepare') [enabled by default] > > > > make[1]: *** [arch/arm64/kernel/psci.o] Error 1 > > > > > > > > The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is > > > > defined, not CPU_IDLE. > > > > > > > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > > > > > > > > > No objection to fixing this obvious build bug, but why do we even have > > > an ARM64_CPU_SUSPEND option? On ARM32 we only have the respective option > > > because we have a random collection of platform specific drivers that > > > use the symbols, but that's not the case on ARM64. > > > > I believe because of cpuidle. It's the same as on ARM32: the cpu_suspend > > is used by both PM_SLEEP and CPU_IDLE. > > I guess at some point we can replace (as a separate patch) > ARM64_CPU_SUSPEND with PM_SLEEP. > > But what I don't fully understand, we can enable CPU_IDLE without > ARM64_CPU_SUSPEND. However, the cpuidle-arm64.c driver will fail to > link since it calls cpu_suspend(). Wouldn't it be better if > ARM64_CPU_SUSPEND depends on CPU_PM (or replaced by it) rather than > PM_SLEEP? I think that ARM64_CPU_SUSPEND should depend on PM_SLEEP || CPU_IDLE, if CPU_IDLE is enabled it is certainly because some idle states are expected to be present, true, not all of them lose context (which is why ARM64_CPU_SUSPEND is needed, to save/restore context and clean it to RAM), but I think that's too fine grain, making it depend on CPU_IDLE should be ok. Having CPU_IDLE enabled without arm64 cpuidle driver enabled (which selects ARM64_CPU_SUSPEND) is useless at the moment. As to cpu_ops, I think that the suspend hook should ifdef on CPU_IDLE, but I have to wait and see how we implement S2R to make it a final decision. > Can we allow deeper idle states when CONFIG_SUSPEND is disabled? I see > CONFIG_SUSPEND related to suspend-to-RAM (system standby) rather than > CPU idle, in which case we may want to allow cpu_suspend when only > CPU_IDLE is enabled (which implies CONFIG_CPU_PM). Yes, deep idle states are enabled even when suspend is disabled, but both S2R and CPU_IDLE should turn on ARM64_CPU_SUSPEND to save/restore context, unless we remove ARM64_CPU_SUSPEND entirely and we always compile that code in. I will put together a patch first thing next week to clarify this thread. Thanks, Lorenzo
On Fri, Dec 12, 2014 at 03:06:08PM +0000, Lorenzo Pieralisi wrote: > On Tue, Dec 09, 2014 at 04:15:11PM +0000, Catalin Marinas wrote: > > On Tue, Dec 09, 2014 at 12:38:09PM +0000, Krzysztof Kozlowski wrote: > > > On wto, 2014-12-09 at 13:29 +0100, Arnd Bergmann wrote: > > > > On Tuesday 09 December 2014 12:48:36 Krzysztof Kozlowski wrote: > > > > > Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by > > > > > disabling SUSPEND) and CPU_IDLE enabled: > > > > > > > > > > arch/arm64/kernel/psci.c:543:2: error: unknown field 'cpu_suspend' specified in initializer > > > > > .cpu_suspend = cpu_psci_cpu_suspend, > > > > > ^ > > > > > arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default] > > > > > arch/arm64/kernel/psci.c:543:2: warning: (near initialization for 'cpu_psci_ops.cpu_prepare') [enabled by default] > > > > > make[1]: *** [arch/arm64/kernel/psci.o] Error 1 > > > > > > > > > > The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is > > > > > defined, not CPU_IDLE. > > > > > > > > > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > > > > > > > > > > > > No objection to fixing this obvious build bug, but why do we even have > > > > an ARM64_CPU_SUSPEND option? On ARM32 we only have the respective option > > > > because we have a random collection of platform specific drivers that > > > > use the symbols, but that's not the case on ARM64. > > > > > > I believe because of cpuidle. It's the same as on ARM32: the cpu_suspend > > > is used by both PM_SLEEP and CPU_IDLE. > > > > I guess at some point we can replace (as a separate patch) > > ARM64_CPU_SUSPEND with PM_SLEEP. > > > > But what I don't fully understand, we can enable CPU_IDLE without > > ARM64_CPU_SUSPEND. However, the cpuidle-arm64.c driver will fail to > > link since it calls cpu_suspend(). Wouldn't it be better if > > ARM64_CPU_SUSPEND depends on CPU_PM (or replaced by it) rather than > > PM_SLEEP? > > I think that ARM64_CPU_SUSPEND should depend on PM_SLEEP || CPU_IDLE, That's what we do with CPU_PM, we select it if SUSPEND || CPU_IDLE (PM_SLEEP is default yes if SUSPEND). > if CPU_IDLE is enabled it is certainly because some idle states are > expected to be present, true, not all of them lose context (which is > why ARM64_CPU_SUSPEND is needed, to save/restore context and clean > it to RAM), but I think that's too fine grain, making it depend on > CPU_IDLE should be ok. > > Having CPU_IDLE enabled without arm64 cpuidle driver enabled (which > selects ARM64_CPU_SUSPEND) is useless at the moment. Ah, so we can force a selection even if it doesn't meet its dependencies like PM_SLEEP (which depends on SUSPEND). Can we just get rid of ARM64_CPU_SUSPEND altogether and use CPU_PM instead?
On Mon, Dec 15, 2014 at 05:46:22PM +0000, Catalin Marinas wrote: > On Fri, Dec 12, 2014 at 03:06:08PM +0000, Lorenzo Pieralisi wrote: > > On Tue, Dec 09, 2014 at 04:15:11PM +0000, Catalin Marinas wrote: > > > On Tue, Dec 09, 2014 at 12:38:09PM +0000, Krzysztof Kozlowski wrote: > > > > On wto, 2014-12-09 at 13:29 +0100, Arnd Bergmann wrote: > > > > > On Tuesday 09 December 2014 12:48:36 Krzysztof Kozlowski wrote: > > > > > > Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by > > > > > > disabling SUSPEND) and CPU_IDLE enabled: > > > > > > > > > > > > arch/arm64/kernel/psci.c:543:2: error: unknown field 'cpu_suspend' specified in initializer > > > > > > .cpu_suspend = cpu_psci_cpu_suspend, > > > > > > ^ > > > > > > arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default] > > > > > > arch/arm64/kernel/psci.c:543:2: warning: (near initialization for 'cpu_psci_ops.cpu_prepare') [enabled by default] > > > > > > make[1]: *** [arch/arm64/kernel/psci.o] Error 1 > > > > > > > > > > > > The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is > > > > > > defined, not CPU_IDLE. > > > > > > > > > > > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > > > > > > > > > > > > > > > No objection to fixing this obvious build bug, but why do we even have > > > > > an ARM64_CPU_SUSPEND option? On ARM32 we only have the respective option > > > > > because we have a random collection of platform specific drivers that > > > > > use the symbols, but that's not the case on ARM64. > > > > > > > > I believe because of cpuidle. It's the same as on ARM32: the cpu_suspend > > > > is used by both PM_SLEEP and CPU_IDLE. > > > > > > I guess at some point we can replace (as a separate patch) > > > ARM64_CPU_SUSPEND with PM_SLEEP. > > > > > > But what I don't fully understand, we can enable CPU_IDLE without > > > ARM64_CPU_SUSPEND. However, the cpuidle-arm64.c driver will fail to > > > link since it calls cpu_suspend(). Wouldn't it be better if > > > ARM64_CPU_SUSPEND depends on CPU_PM (or replaced by it) rather than > > > PM_SLEEP? > > > > I think that ARM64_CPU_SUSPEND should depend on PM_SLEEP || CPU_IDLE, > > That's what we do with CPU_PM, we select it if SUSPEND || CPU_IDLE > (PM_SLEEP is default yes if SUSPEND). > > > if CPU_IDLE is enabled it is certainly because some idle states are > > expected to be present, true, not all of them lose context (which is > > why ARM64_CPU_SUSPEND is needed, to save/restore context and clean > > it to RAM), but I think that's too fine grain, making it depend on > > CPU_IDLE should be ok. > > > > Having CPU_IDLE enabled without arm64 cpuidle driver enabled (which > > selects ARM64_CPU_SUSPEND) is useless at the moment. > > Ah, so we can force a selection even if it doesn't meet its > dependencies like PM_SLEEP (which depends on SUSPEND). > > Can we just get rid of ARM64_CPU_SUSPEND altogether and use CPU_PM > instead? Yes, it looks like the best option to me, I will put together a patch shortly. Thanks, Lorenzo
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index 3425f311c49e..f1dbca7d5c96 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -540,6 +540,8 @@ const struct cpu_operations cpu_psci_ops = { .name = "psci", #ifdef CONFIG_CPU_IDLE .cpu_init_idle = cpu_psci_cpu_init_idle, +#endif +#ifdef CONFIG_ARM64_CPU_SUSPEND .cpu_suspend = cpu_psci_cpu_suspend, #endif #ifdef CONFIG_SMP
Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by disabling SUSPEND) and CPU_IDLE enabled: arch/arm64/kernel/psci.c:543:2: error: unknown field ‘cpu_suspend’ specified in initializer .cpu_suspend = cpu_psci_cpu_suspend, ^ arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default] arch/arm64/kernel/psci.c:543:2: warning: (near initialization for ‘cpu_psci_ops.cpu_prepare’) [enabled by default] make[1]: *** [arch/arm64/kernel/psci.o] Error 1 The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is defined, not CPU_IDLE. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> --- arch/arm64/kernel/psci.c | 2 ++ 1 file changed, 2 insertions(+)