* Re: [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend
2024-10-11 0:36 ` [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend David E. Box
@ 2024-10-11 2:09 ` srinivas pandruvada
2024-10-11 3:50 ` David E. Box
2024-10-11 11:05 ` Rafael J. Wysocki
2024-10-13 0:40 ` srinivas pandruvada
2 siblings, 1 reply; 7+ messages in thread
From: srinivas pandruvada @ 2024-10-11 2:09 UTC (permalink / raw)
To: David E. Box, hdegoede, ilpo.jarvinen, rjw, platform-driver-x86,
linux-kernel, linux-pm
On Thu, 2024-10-10 at 17:36 -0700, David E. Box wrote:
> On some platforms, aggressive C1 auto-demotion may lead to failure to
> enter
> the deepest C-state during suspend-to-idle, causing high power
> consumption.
> To prevent this, disable C1 auto-demotion during suspend and re-
> enable on
> resume.
>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
>
> V2 - Remove #define DEBUG
> - Move refactor of cnl_resume() to separate patch
> - Use smp_call_function() to disable and restore C1_AUTO_DEMOTE
> - Add comment that the MSR is per core, not per package.
> - Add comment that the online cpu mask remains unchanged during
> suspend due to frozen userspace.
>
> drivers/platform/x86/intel/pmc/cnp.c | 53
> ++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/drivers/platform/x86/intel/pmc/cnp.c
> b/drivers/platform/x86/intel/pmc/cnp.c
> index 513c02670c5a..f12d4f0f9e93 100644
> --- a/drivers/platform/x86/intel/pmc/cnp.c
> +++ b/drivers/platform/x86/intel/pmc/cnp.c
> @@ -8,6 +8,8 @@
> *
> */
>
> +#include <linux/smp.h>
> +#include <linux/suspend.h>
> #include "core.h"
>
> /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
> @@ -206,8 +208,52 @@ const struct pmc_reg_map cnp_reg_map = {
> .etr3_offset = ETR3_OFFSET,
> };
>
> +
> +/*
> + * Disable C1 auto-demotion
> + *
> + * Aggressive C1 auto-demotion may lead to failure to enter the
> deepest C-state
> + * during suspend-to-idle, causing high power consumption. To
> prevent this, we
> + * disable C1 auto-demotion during suspend and re-enable on resume.
> + *
> + * Note that, although MSR_PKG_CST_CONFIG_CONTROL has 'package' in
> its name, it
> + * is actually a per-core MSR on client platforms, affecting only a
> single CPU.
> + * Therefore, it must be configured on all online CPUs. The online
> cpu mask is
> + * unchanged during the phase of suspend/resume as user space is
> frozen.
> + */
> +
> +static DEFINE_PER_CPU(u64, pkg_cst_config);
> +
> +static void disable_c1_auto_demote(void *unused)
> +{
> + int cpunum = smp_processor_id();
> + u64 val;
> +
> + rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> + per_cpu(pkg_cst_config, cpunum) = val;
> + val &= ~NHM_C1_AUTO_DEMOTE;
> + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum, val);
Do you want to leave pr_debug?
> +}
> +
> +static void restore_c1_auto_demote(void *unused)
> +{
> + int cpunum = smp_processor_id();
> +
> + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum,
> + per_cpu(pkg_cst_config, cpunum));
> + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, per_cpu(pkg_cst_config,
> cpunum));
> +}
> +
> void cnl_suspend(struct pmc_dev *pmcdev)
> {
> + if (!pm_suspend_via_firmware()) {
> + preempt_disable();
Why do you need this?
Thanks,
Srinivas
> + disable_c1_auto_demote(NULL);
> + smp_call_function(disable_c1_auto_demote, NULL, 0);
> + preempt_enable();
> + }
> +
> /*
> * Due to a hardware limitation, the GBE LTR blocks PC10
> * when a cable is attached. To unblock PC10 during suspend,
> @@ -218,6 +264,13 @@ void cnl_suspend(struct pmc_dev *pmcdev)
>
> int cnl_resume(struct pmc_dev *pmcdev)
> {
> + if (!pm_suspend_via_firmware()) {
> + preempt_disable();
> + restore_c1_auto_demote(NULL);
> + smp_call_function(restore_c1_auto_demote, NULL, 0);
> + preempt_enable();
> + }
> +
> pmc_core_send_ltr_ignore(pmcdev, 3, 0);
>
> return pmc_core_resume_common(pmcdev);
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend
2024-10-11 2:09 ` srinivas pandruvada
@ 2024-10-11 3:50 ` David E. Box
2024-10-11 16:36 ` srinivas pandruvada
0 siblings, 1 reply; 7+ messages in thread
From: David E. Box @ 2024-10-11 3:50 UTC (permalink / raw)
To: srinivas pandruvada, hdegoede, ilpo.jarvinen, rjw,
platform-driver-x86, linux-kernel, linux-pm
On Thu, 2024-10-10 at 19:09 -0700, srinivas pandruvada wrote:
> On Thu, 2024-10-10 at 17:36 -0700, David E. Box wrote:
> > On some platforms, aggressive C1 auto-demotion may lead to failure to
> > enter
> > the deepest C-state during suspend-to-idle, causing high power
> > consumption.
> > To prevent this, disable C1 auto-demotion during suspend and re-
> > enable on
> > resume.
> >
> > Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> > ---
> >
> > V2 - Remove #define DEBUG
> > - Move refactor of cnl_resume() to separate patch
> > - Use smp_call_function() to disable and restore C1_AUTO_DEMOTE
> > - Add comment that the MSR is per core, not per package.
> > - Add comment that the online cpu mask remains unchanged during
> > suspend due to frozen userspace.
> >
> > drivers/platform/x86/intel/pmc/cnp.c | 53
> > ++++++++++++++++++++++++++++
> > 1 file changed, 53 insertions(+)
> >
> > diff --git a/drivers/platform/x86/intel/pmc/cnp.c
> > b/drivers/platform/x86/intel/pmc/cnp.c
> > index 513c02670c5a..f12d4f0f9e93 100644
> > --- a/drivers/platform/x86/intel/pmc/cnp.c
> > +++ b/drivers/platform/x86/intel/pmc/cnp.c
> > @@ -8,6 +8,8 @@
> > *
> > */
> >
> > +#include <linux/smp.h>
> > +#include <linux/suspend.h>
> > #include "core.h"
> >
> > /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
> > @@ -206,8 +208,52 @@ const struct pmc_reg_map cnp_reg_map = {
> > .etr3_offset = ETR3_OFFSET,
> > };
> >
> > +
> > +/*
> > + * Disable C1 auto-demotion
> > + *
> > + * Aggressive C1 auto-demotion may lead to failure to enter the
> > deepest C-state
> > + * during suspend-to-idle, causing high power consumption. To
> > prevent this, we
> > + * disable C1 auto-demotion during suspend and re-enable on resume.
> > + *
> > + * Note that, although MSR_PKG_CST_CONFIG_CONTROL has 'package' in
> > its name, it
> > + * is actually a per-core MSR on client platforms, affecting only a
> > single CPU.
> > + * Therefore, it must be configured on all online CPUs. The online
> > cpu mask is
> > + * unchanged during the phase of suspend/resume as user space is
> > frozen.
> > + */
> > +
> > +static DEFINE_PER_CPU(u64, pkg_cst_config);
> > +
> > +static void disable_c1_auto_demote(void *unused)
> > +{
> > + int cpunum = smp_processor_id();
> > + u64 val;
> > +
> > + rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> > + per_cpu(pkg_cst_config, cpunum) = val;
> > + val &= ~NHM_C1_AUTO_DEMOTE;
> > + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> > + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum, val);
> Do you want to leave pr_debug?
Thought it could be useful but it can be removed.
>
> > +}
> > +
> > +static void restore_c1_auto_demote(void *unused)
> > +{
> > + int cpunum = smp_processor_id();
> > +
> > + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum,
> > + per_cpu(pkg_cst_config, cpunum));
> > + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, per_cpu(pkg_cst_config,
> > cpunum));
> > +}
> > +
> > void cnl_suspend(struct pmc_dev *pmcdev)
> > {
> > + if (!pm_suspend_via_firmware()) {
> > + preempt_disable();
> Why do you need this?
To ensure that the cpu doesn't change between the next two calls.
David
>
>
> Thanks,
> Srinivas
>
> > + disable_c1_auto_demote(NULL);
> > + smp_call_function(disable_c1_auto_demote, NULL, 0);
> > + preempt_enable();
> > + }
> > +
> > /*
> > * Due to a hardware limitation, the GBE LTR blocks PC10
> > * when a cable is attached. To unblock PC10 during suspend,
> > @@ -218,6 +264,13 @@ void cnl_suspend(struct pmc_dev *pmcdev)
> >
> > int cnl_resume(struct pmc_dev *pmcdev)
> > {
> > + if (!pm_suspend_via_firmware()) {
> > + preempt_disable();
> > + restore_c1_auto_demote(NULL);
> > + smp_call_function(restore_c1_auto_demote, NULL, 0);
> > + preempt_enable();
> > + }
> > +
> > pmc_core_send_ltr_ignore(pmcdev, 3, 0);
> >
> > return pmc_core_resume_common(pmcdev);
>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend
2024-10-11 3:50 ` David E. Box
@ 2024-10-11 16:36 ` srinivas pandruvada
0 siblings, 0 replies; 7+ messages in thread
From: srinivas pandruvada @ 2024-10-11 16:36 UTC (permalink / raw)
To: david.e.box, hdegoede, ilpo.jarvinen, rjw, platform-driver-x86,
linux-kernel, linux-pm
On Thu, 2024-10-10 at 20:50 -0700, David E. Box wrote:
> On Thu, 2024-10-10 at 19:09 -0700, srinivas pandruvada wrote:
> > On Thu, 2024-10-10 at 17:36 -0700, David E. Box wrote:
> > > On some platforms, aggressive C1 auto-demotion may lead to
> > > failure to
> > > enter
> > > the deepest C-state during suspend-to-idle, causing high power
> > > consumption.
> > > To prevent this, disable C1 auto-demotion during suspend and re-
> > > enable on
> > > resume.
> > >
> > > Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> > > ---
> > >
> > > V2 - Remove #define DEBUG
> > > - Move refactor of cnl_resume() to separate patch
> > > - Use smp_call_function() to disable and restore
> > > C1_AUTO_DEMOTE
> > > - Add comment that the MSR is per core, not per package.
> > > - Add comment that the online cpu mask remains unchanged
> > > during
> > > suspend due to frozen userspace.
> > >
> > > drivers/platform/x86/intel/pmc/cnp.c | 53
> > > ++++++++++++++++++++++++++++
> > > 1 file changed, 53 insertions(+)
> > >
> > > diff --git a/drivers/platform/x86/intel/pmc/cnp.c
> > > b/drivers/platform/x86/intel/pmc/cnp.c
> > > index 513c02670c5a..f12d4f0f9e93 100644
> > > --- a/drivers/platform/x86/intel/pmc/cnp.c
> > > +++ b/drivers/platform/x86/intel/pmc/cnp.c
> > > @@ -8,6 +8,8 @@
> > > *
> > > */
> > >
> > > +#include <linux/smp.h>
> > > +#include <linux/suspend.h>
> > > #include "core.h"
> > >
> > > /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
> > > @@ -206,8 +208,52 @@ const struct pmc_reg_map cnp_reg_map = {
> > > .etr3_offset = ETR3_OFFSET,
> > > };
> > >
> > > +
> > > +/*
> > > + * Disable C1 auto-demotion
> > > + *
> > > + * Aggressive C1 auto-demotion may lead to failure to enter the
> > > deepest C-state
> > > + * during suspend-to-idle, causing high power consumption. To
> > > prevent this, we
> > > + * disable C1 auto-demotion during suspend and re-enable on
> > > resume.
> > > + *
> > > + * Note that, although MSR_PKG_CST_CONFIG_CONTROL has 'package'
> > > in
> > > its name, it
> > > + * is actually a per-core MSR on client platforms, affecting
> > > only a
> > > single CPU.
> > > + * Therefore, it must be configured on all online CPUs. The
> > > online
> > > cpu mask is
> > > + * unchanged during the phase of suspend/resume as user space is
> > > frozen.
> > > + */
> > > +
> > > +static DEFINE_PER_CPU(u64, pkg_cst_config);
> > > +
> > > +static void disable_c1_auto_demote(void *unused)
> > > +{
> > > + int cpunum = smp_processor_id();
> > > + u64 val;
> > > +
> > > + rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> > > + per_cpu(pkg_cst_config, cpunum) = val;
> > > + val &= ~NHM_C1_AUTO_DEMOTE;
> > > + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> > > + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum,
> > > val);
> > Do you want to leave pr_debug?
>
> Thought it could be useful but it can be removed.
>
> >
> > > +}
> > > +
> > > +static void restore_c1_auto_demote(void *unused)
> > > +{
> > > + int cpunum = smp_processor_id();
> > > +
> > > + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum,
> > > + per_cpu(pkg_cst_config, cpunum));
> > > + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL,
> > > per_cpu(pkg_cst_config,
> > > cpunum));
> > > +}
> > > +
> > > void cnl_suspend(struct pmc_dev *pmcdev)
> > > {
> > > + if (!pm_suspend_via_firmware()) {
> > > + preempt_disable();
> > Why do you need this?
>
> To ensure that the cpu doesn't change between the next two calls.
Correct. You need for smp_processor_id()
Generally for this avoiding issue with smp_processor_id(), you can use
get_cpu(), which gives current cpu as return value and also disable
preemption.
Something like this
this_cpu = get_cpu();
disable_c1_auto_demote(&this_cpu);
smp_call_function_many(cpu_online_mask, disable_c1_auto_demote, NULL,
0);
put_cpu();
But fine, this makes your code more complex as you have to pass now a
param and use for local_cpu and use smp_procesor_id() for remote call
via smp_call..
Thanks,
Srinivas
>
> David
>
> >
> >
> > Thanks,
> > Srinivas
> >
> > > + disable_c1_auto_demote(NULL);
> > > + smp_call_function(disable_c1_auto_demote, NULL,
> > > 0);
> > > + preempt_enable();
> > > + }
> > > +
> > > /*
> > > * Due to a hardware limitation, the GBE LTR blocks PC10
> > > * when a cable is attached. To unblock PC10 during
> > > suspend,
> > > @@ -218,6 +264,13 @@ void cnl_suspend(struct pmc_dev *pmcdev)
> > >
> > > int cnl_resume(struct pmc_dev *pmcdev)
> > > {
> > > + if (!pm_suspend_via_firmware()) {
> > > + preempt_disable();
> > > + restore_c1_auto_demote(NULL);
> > > + smp_call_function(restore_c1_auto_demote, NULL,
> > > 0);
> > > + preempt_enable();
> > > + }
> > > +
> > > pmc_core_send_ltr_ignore(pmcdev, 3, 0);
> > >
> > > return pmc_core_resume_common(pmcdev);
> >
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend
2024-10-11 0:36 ` [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend David E. Box
2024-10-11 2:09 ` srinivas pandruvada
@ 2024-10-11 11:05 ` Rafael J. Wysocki
2024-10-13 0:40 ` srinivas pandruvada
2 siblings, 0 replies; 7+ messages in thread
From: Rafael J. Wysocki @ 2024-10-11 11:05 UTC (permalink / raw)
To: David E. Box
Cc: hdegoede, ilpo.jarvinen, rjw, srinivas.pandruvada,
platform-driver-x86, linux-kernel, linux-pm
On Fri, Oct 11, 2024 at 2:36 AM David E. Box
<david.e.box@linux.intel.com> wrote:
>
> On some platforms, aggressive C1 auto-demotion may lead to failure to enter
> the deepest C-state during suspend-to-idle, causing high power consumption.
> To prevent this, disable C1 auto-demotion during suspend and re-enable on
> resume.
>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
>
> V2 - Remove #define DEBUG
> - Move refactor of cnl_resume() to separate patch
> - Use smp_call_function() to disable and restore C1_AUTO_DEMOTE
> - Add comment that the MSR is per core, not per package.
> - Add comment that the online cpu mask remains unchanged during
> suspend due to frozen userspace.
>
> drivers/platform/x86/intel/pmc/cnp.c | 53 ++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
> index 513c02670c5a..f12d4f0f9e93 100644
> --- a/drivers/platform/x86/intel/pmc/cnp.c
> +++ b/drivers/platform/x86/intel/pmc/cnp.c
> @@ -8,6 +8,8 @@
> *
> */
>
> +#include <linux/smp.h>
> +#include <linux/suspend.h>
> #include "core.h"
>
> /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
> @@ -206,8 +208,52 @@ const struct pmc_reg_map cnp_reg_map = {
> .etr3_offset = ETR3_OFFSET,
> };
>
> +
> +/*
> + * Disable C1 auto-demotion
> + *
> + * Aggressive C1 auto-demotion may lead to failure to enter the deepest C-state
> + * during suspend-to-idle, causing high power consumption. To prevent this, we
> + * disable C1 auto-demotion during suspend and re-enable on resume.
> + *
> + * Note that, although MSR_PKG_CST_CONFIG_CONTROL has 'package' in its name, it
> + * is actually a per-core MSR on client platforms, affecting only a single CPU.
> + * Therefore, it must be configured on all online CPUs. The online cpu mask is
> + * unchanged during the phase of suspend/resume as user space is frozen.
> + */
> +
> +static DEFINE_PER_CPU(u64, pkg_cst_config);
> +
> +static void disable_c1_auto_demote(void *unused)
> +{
> + int cpunum = smp_processor_id();
> + u64 val;
> +
> + rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> + per_cpu(pkg_cst_config, cpunum) = val;
> + val &= ~NHM_C1_AUTO_DEMOTE;
> + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum, val);
> +}
If you decide to retain the debug statements, I generally prefer to
separate them from the rest of the code with empty lines, for clarity.
> +
> +static void restore_c1_auto_demote(void *unused)
> +{
> + int cpunum = smp_processor_id();
> +
> + pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum,
> + per_cpu(pkg_cst_config, cpunum));
> + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, per_cpu(pkg_cst_config, cpunum));
> +}
> +
I would add something like
static void s2idle_cpu_quirk(smp_call_func_t func)
{
if (pm_suspend_via_firmware())
return;
preempt_disable();
func();
smp_call_function(func, NULL, 0);
preempt_enable();
}
> void cnl_suspend(struct pmc_dev *pmcdev)
> {
> + if (!pm_suspend_via_firmware()) {
> + preempt_disable();
> + disable_c1_auto_demote(NULL);
> + smp_call_function(disable_c1_auto_demote, NULL, 0);
> + preempt_enable();
> + }
> +
And here I'd just do
s2idle_cpu_quirk(disable_c1_auto_demote);
and analogously below.
> /*
> * Due to a hardware limitation, the GBE LTR blocks PC10
> * when a cable is attached. To unblock PC10 during suspend,
> @@ -218,6 +264,13 @@ void cnl_suspend(struct pmc_dev *pmcdev)
>
> int cnl_resume(struct pmc_dev *pmcdev)
> {
> + if (!pm_suspend_via_firmware()) {
> + preempt_disable();
> + restore_c1_auto_demote(NULL);
> + smp_call_function(restore_c1_auto_demote, NULL, 0);
> + preempt_enable();
> + }
> +
> pmc_core_send_ltr_ignore(pmcdev, 3, 0);
>
> return pmc_core_resume_common(pmcdev);
> --
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend
2024-10-11 0:36 ` [PATCH V2 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend David E. Box
2024-10-11 2:09 ` srinivas pandruvada
2024-10-11 11:05 ` Rafael J. Wysocki
@ 2024-10-13 0:40 ` srinivas pandruvada
2 siblings, 0 replies; 7+ messages in thread
From: srinivas pandruvada @ 2024-10-13 0:40 UTC (permalink / raw)
To: David E. Box, hdegoede, ilpo.jarvinen, rjw, platform-driver-x86,
linux-kernel, linux-pm
Cc: ricardo.neri-calderon
+Ricardo
On Thu, 2024-10-10 at 17:36 -0700, David E. Box wrote:
> On some platforms, aggressive C1 auto-demotion may lead to failure to
> enter
> the deepest C-state during suspend-to-idle, causing high power
> consumption.
> To prevent this, disable C1 auto-demotion during suspend and re-
> enable on
> resume.
>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
>
[...]
> void cnl_suspend(struct pmc_dev *pmcdev)
> {
> + if (!pm_suspend_via_firmware()) {
> + preempt_disable();
> + disable_c1_auto_demote(NULL);
> + smp_call_function(disable_c1_auto_demote, NULL, 0);
> + preempt_enable();
> + }
>
As suggested by Ricardo using the following will work avoiding separate
local CPU call. Preemption will be disabled, no need separate call.
Also cpu_online_mask can't be changed during these callbacks.
if (!pm_suspend_via_firmware())
on_each_cpu(disable_c1_auto_demote, NULL, true);
I think you need wait=true. I have seen on some occasions you will miss
msr write as we called mwait before before async calls finished.
Thanks,
Srinivas
> +
> /*
> * Due to a hardware limitation, the GBE LTR blocks PC10
> * when a cable is attached. To unblock PC10 during suspend,
> @@ -218,6 +264,13 @@ void cnl_suspend(struct pmc_dev *pmcdev)
>
> int cnl_resume(struct pmc_dev *pmcdev)
> {
> + if (!pm_suspend_via_firmware()) {
> + preempt_disable();
> + restore_c1_auto_demote(NULL);
> + smp_call_function(restore_c1_auto_demote, NULL, 0);
> + preempt_enable();
> + }
> +
> pmc_core_send_ltr_ignore(pmcdev, 3, 0);
>
> return pmc_core_resume_common(pmcdev);
^ permalink raw reply [flat|nested] 7+ messages in thread