* [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
@ 2021-09-09 3:48 Doug Smythies
2021-09-09 6:33 ` Srinivas Pandruvada
0 siblings, 1 reply; 13+ messages in thread
From: Doug Smythies @ 2021-09-09 3:48 UTC (permalink / raw)
To: srinivas.pandruvada, rafael, len.brown; +Cc: dsmythies, linux-kernel, linux-pm
If HWP has been already been enabled by BIOS, it may be
necessary to override some kernel command line parameters.
Once it has been enabled it requires a reset to be disabled.
Signed-off-by: Doug Smythies <dsmythies@telus.net>
---
drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index bb4549959b11..073bae5d4498 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
*/
if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
intel_pstate_hwp_is_enabled()) {
- hwp_active++;
+ hwp_active = 1;
hwp_mode_bdw = id->driver_data;
intel_pstate.attr = hwp_cpufreq_attrs;
intel_cpufreq.attr = hwp_cpufreq_attrs;
@@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
static int __init intel_pstate_setup(char *str)
{
+ /*
+ * If BIOS is forcing HWP, then parameter
+ * overrides might be needed. Only print
+ * the message once, and regardless of
+ * any overrides.
+ */
+ if(!hwp_active && boot_cpu_has(X86_FEATURE_HWP))
+ if(intel_pstate_hwp_is_enabled()){
+ pr_info("HWP enabled by BIOS\n");
+ hwp_active = 1;
+ }
if (!str)
return -EINVAL;
- if (!strcmp(str, "disable"))
+ if (!strcmp(str, "disable") && !hwp_active)
no_load = 1;
- else if (!strcmp(str, "active"))
+ if (!strcmp(str, "active"))
default_driver = &intel_pstate;
- else if (!strcmp(str, "passive"))
+ if (!strcmp(str, "passive"))
default_driver = &intel_cpufreq;
-
- if (!strcmp(str, "no_hwp")) {
+ if (!strcmp(str, "no_hwp") && !hwp_active) {
pr_info("HWP disabled\n");
no_hwp = 1;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 3:48 [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS Doug Smythies
@ 2021-09-09 6:33 ` Srinivas Pandruvada
2021-09-09 11:18 ` Rafael J. Wysocki
2021-09-09 13:30 ` Doug Smythies
0 siblings, 2 replies; 13+ messages in thread
From: Srinivas Pandruvada @ 2021-09-09 6:33 UTC (permalink / raw)
To: Doug Smythies, rafael, len.brown; +Cc: dsmythies, linux-kernel, linux-pm
On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> If HWP has been already been enabled by BIOS, it may be
> necessary to override some kernel command line parameters.
> Once it has been enabled it requires a reset to be disabled.
>
> Signed-off-by: Doug Smythies <dsmythies@telus.net>
> ---
> drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> 1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/cpufreq/intel_pstate.c
> b/drivers/cpufreq/intel_pstate.c
> index bb4549959b11..073bae5d4498 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> */
> if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> intel_pstate_hwp_is_enabled()) {
> - hwp_active++;
> + hwp_active = 1;
Why this change?
> hwp_mode_bdw = id->driver_data;
> intel_pstate.attr = hwp_cpufreq_attrs;
> intel_cpufreq.attr = hwp_cpufreq_attrs;
> @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
>
> static int __init intel_pstate_setup(char *str)
> {
> + /*
> + * If BIOS is forcing HWP, then parameter
> + * overrides might be needed. Only print
> + * the message once, and regardless of
> + * any overrides.
> + */
> + if(!hwp_active
This part of code is from early_param, Is it possible that
hwp_active is not 0?
> && boot_cpu_has(X86_FEATURE_HWP))
> + if(intel_pstate_hwp_is_enabled()){
> + pr_info("HWP enabled by BIOS\n");
> + hwp_active = 1;
> + }
> if (!str)
> return -EINVAL;
>
> - if (!strcmp(str, "disable"))
> + if (!strcmp(str, "disable") && !hwp_active)
> no_load = 1;
> - else if (!strcmp(str, "active"))
> + if (!strcmp(str, "active"))
> default_driver = &intel_pstate;
> - else if (!strcmp(str, "passive"))
> + if (!strcmp(str, "passive"))
> default_driver = &intel_cpufreq;
Why "else if" changed to "if" ?
Thanks,
Srinivas
> -
> - if (!strcmp(str, "no_hwp")) {
> + if (!strcmp(str, "no_hwp") && !hwp_active) {
> pr_info("HWP disabled\n");
> no_hwp = 1;
> }
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 6:33 ` Srinivas Pandruvada
@ 2021-09-09 11:18 ` Rafael J. Wysocki
2021-09-09 13:20 ` Doug Smythies
2021-09-09 13:30 ` Doug Smythies
1 sibling, 1 reply; 13+ messages in thread
From: Rafael J. Wysocki @ 2021-09-09 11:18 UTC (permalink / raw)
To: Srinivas Pandruvada, Doug Smythies
Cc: Rafael J. Wysocki, Len Brown, Doug Smythies,
Linux Kernel Mailing List, Linux PM
On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
>
> On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > If HWP has been already been enabled by BIOS, it may be
> > necessary to override some kernel command line parameters.
> > Once it has been enabled it requires a reset to be disabled.
> >
> > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > ---
> > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > 1 file changed, 16 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/cpufreq/intel_pstate.c
> > b/drivers/cpufreq/intel_pstate.c
> > index bb4549959b11..073bae5d4498 100644
> > --- a/drivers/cpufreq/intel_pstate.c
> > +++ b/drivers/cpufreq/intel_pstate.c
> > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > */
> > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > intel_pstate_hwp_is_enabled()) {
> > - hwp_active++;
> > + hwp_active = 1;
> Why this change?
I think hwp_active can be changed to bool and then it would make sense
to update this line.
> > hwp_mode_bdw = id->driver_data;
> > intel_pstate.attr = hwp_cpufreq_attrs;
> > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> >
> > static int __init intel_pstate_setup(char *str)
> > {
> > + /*
> > + * If BIOS is forcing HWP, then parameter
> > + * overrides might be needed. Only print
> > + * the message once, and regardless of
> > + * any overrides.
> > + */
> > + if(!hwp_active
> This part of code is from early_param, Is it possible that
> hwp_active is not 0?
Well, it wouldn't matter even if it were nonzero. This check is just
pointless anyway.
> > && boot_cpu_has(X86_FEATURE_HWP))
> > + if(intel_pstate_hwp_is_enabled()){
This should be
if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
> > + pr_info("HWP enabled by BIOS\n");
> > + hwp_active = 1;
> > + }
> > if (!str)
> > return -EINVAL;
> >
> > - if (!strcmp(str, "disable"))
> > + if (!strcmp(str, "disable") && !hwp_active)
> > no_load = 1;
> > - else if (!strcmp(str, "active"))
> > + if (!strcmp(str, "active"))
> > default_driver = &intel_pstate;
> > - else if (!strcmp(str, "passive"))
> > + if (!strcmp(str, "passive"))
> > default_driver = &intel_cpufreq;
>
> Why "else if" changed to "if" ?
>
> > -
> > - if (!strcmp(str, "no_hwp")) {
> > + if (!strcmp(str, "no_hwp") && !hwp_active) {
> > pr_info("HWP disabled\n");
> > no_hwp = 1;
> > }
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 11:18 ` Rafael J. Wysocki
@ 2021-09-09 13:20 ` Doug Smythies
2021-09-09 16:12 ` Rafael J. Wysocki
0 siblings, 1 reply; 13+ messages in thread
From: Doug Smythies @ 2021-09-09 13:20 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Srinivas Pandruvada, Len Brown, Linux Kernel Mailing List,
Linux PM, dsmythies
On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
> <srinivas.pandruvada@linux.intel.com> wrote:
> >
> > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > If HWP has been already been enabled by BIOS, it may be
> > > necessary to override some kernel command line parameters.
> > > Once it has been enabled it requires a reset to be disabled.
> > >
> > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > ---
> > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > b/drivers/cpufreq/intel_pstate.c
> > > index bb4549959b11..073bae5d4498 100644
> > > --- a/drivers/cpufreq/intel_pstate.c
> > > +++ b/drivers/cpufreq/intel_pstate.c
> > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > */
> > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > intel_pstate_hwp_is_enabled()) {
> > > - hwp_active++;
> > > + hwp_active = 1;
> > Why this change?
>
> I think hwp_active can be changed to bool and then it would make sense
> to update this line.
>
> > > hwp_mode_bdw = id->driver_data;
> > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > >
> > > static int __init intel_pstate_setup(char *str)
> > > {
> > > + /*
> > > + * If BIOS is forcing HWP, then parameter
> > > + * overrides might be needed. Only print
> > > + * the message once, and regardless of
> > > + * any overrides.
> > > + */
> > > + if(!hwp_active
> > This part of code is from early_param, Is it possible that
> > hwp_active is not 0?
>
> Well, it wouldn't matter even if it were nonzero. This check is just
> pointless anyway.
>
> > > && boot_cpu_has(X86_FEATURE_HWP))
> > > + if(intel_pstate_hwp_is_enabled()){
>
> This should be
>
> if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
Disagree.
This routine gets executed once per intel_pstate related grub command
line entry. The purpose of the "if(!hwp_active" part is to prevent the
printing of the message to the logs multiple times.
>
> > > + pr_info("HWP enabled by BIOS\n");
> > > + hwp_active = 1;
> > > + }
> > > if (!str)
> > > return -EINVAL;
> > >
> > > - if (!strcmp(str, "disable"))
> > > + if (!strcmp(str, "disable") && !hwp_active)
> > > no_load = 1;
> > > - else if (!strcmp(str, "active"))
> > > + if (!strcmp(str, "active"))
> > > default_driver = &intel_pstate;
> > > - else if (!strcmp(str, "passive"))
> > > + if (!strcmp(str, "passive"))
> > > default_driver = &intel_cpufreq;
> >
> > Why "else if" changed to "if" ?
> >
> > > -
> > > - if (!strcmp(str, "no_hwp")) {
> > > + if (!strcmp(str, "no_hwp") && !hwp_active) {
> > > pr_info("HWP disabled\n");
> > > no_hwp = 1;
> > > }
> >
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 6:33 ` Srinivas Pandruvada
2021-09-09 11:18 ` Rafael J. Wysocki
@ 2021-09-09 13:30 ` Doug Smythies
2021-09-09 14:52 ` Srinivas Pandruvada
1 sibling, 1 reply; 13+ messages in thread
From: Doug Smythies @ 2021-09-09 13:30 UTC (permalink / raw)
To: Srinivas Pandruvada
Cc: Rafael J. Wysocki, Len Brown, Linux Kernel Mailing List,
Linux PM list, dsmythies
On Wed, Sep 8, 2021 at 11:33 PM Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
>
> On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > If HWP has been already been enabled by BIOS, it may be
> > necessary to override some kernel command line parameters.
> > Once it has been enabled it requires a reset to be disabled.
> >
> > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > ---
> > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > 1 file changed, 16 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/cpufreq/intel_pstate.c
> > b/drivers/cpufreq/intel_pstate.c
> > index bb4549959b11..073bae5d4498 100644
> > --- a/drivers/cpufreq/intel_pstate.c
> > +++ b/drivers/cpufreq/intel_pstate.c
> > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > */
> > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > intel_pstate_hwp_is_enabled()) {
> > - hwp_active++;
> > + hwp_active = 1;
> Why this change?
It was just to keep it at 1, but I agree not absolutely needed.
>
> > hwp_mode_bdw = id->driver_data;
> > intel_pstate.attr = hwp_cpufreq_attrs;
> > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> >
> > static int __init intel_pstate_setup(char *str)
> > {
> > + /*
> > + * If BIOS is forcing HWP, then parameter
> > + * overrides might be needed. Only print
> > + * the message once, and regardless of
> > + * any overrides.
> > + */
> > + if(!hwp_active
> This part of code is from early_param, Is it possible that
> hwp_active is not 0?
Not at this point, in any testing I did.
But I do not know the authoritative answer
to your question.
>
> > && boot_cpu_has(X86_FEATURE_HWP))
> > + if(intel_pstate_hwp_is_enabled()){
> > + pr_info("HWP enabled by BIOS\n");
> > + hwp_active = 1;
> > + }
> > if (!str)
> > return -EINVAL;
> >
> > - if (!strcmp(str, "disable"))
> > + if (!strcmp(str, "disable") && !hwp_active)
> > no_load = 1;
> > - else if (!strcmp(str, "active"))
> > + if (!strcmp(str, "active"))
> > default_driver = &intel_pstate;
> > - else if (!strcmp(str, "passive"))
> > + if (!strcmp(str, "passive"))
> > default_driver = &intel_cpufreq;
>
> Why "else if" changed to "if" ?
Because it doesn't matter anyway and I would
have had to figure out another qualifier.
This way, and given that this executes once per
intel_pstate command line parameter, the code
executes the way it used to, overall.
>
>
> Thanks,
> Srinivas
>
> > -
> > - if (!strcmp(str, "no_hwp")) {
> > + if (!strcmp(str, "no_hwp") && !hwp_active) {
> > pr_info("HWP disabled\n");
> > no_hwp = 1;
> > }
>
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 13:30 ` Doug Smythies
@ 2021-09-09 14:52 ` Srinivas Pandruvada
2021-09-10 4:11 ` Doug Smythies
0 siblings, 1 reply; 13+ messages in thread
From: Srinivas Pandruvada @ 2021-09-09 14:52 UTC (permalink / raw)
To: Doug Smythies
Cc: Rafael J. Wysocki, Len Brown, Linux Kernel Mailing List, Linux PM list
On Thu, 2021-09-09 at 06:30 -0700, Doug Smythies wrote:
> On Wed, Sep 8, 2021 at 11:33 PM Srinivas Pandruvada
> <srinivas.pandruvada@linux.intel.com> wrote:
> >
> > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > If HWP has been already been enabled by BIOS, it may be
> > > necessary to override some kernel command line parameters.
> > > Once it has been enabled it requires a reset to be disabled.
> > >
> > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > ---
> > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > b/drivers/cpufreq/intel_pstate.c
> > > index bb4549959b11..073bae5d4498 100644
> > > --- a/drivers/cpufreq/intel_pstate.c
> > > +++ b/drivers/cpufreq/intel_pstate.c
> > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > */
> > > if ((!no_hwp &&
> > > boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > intel_pstate_hwp_is_enabled()) {
> > > - hwp_active++;
> > > + hwp_active = 1;
> > Why this change?
>
> It was just to keep it at 1, but I agree not absolutely needed.
>
> >
> > > hwp_mode_bdw = id->driver_data;
> > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > >
> > > static int __init intel_pstate_setup(char *str)
> > > {
> > > + /*
> > > + * If BIOS is forcing HWP, then parameter
> > > + * overrides might be needed. Only print
> > > + * the message once, and regardless of
> > > + * any overrides.
> > > + */
> > > + if(!hwp_active
> > This part of code is from early_param, Is it possible that
> > hwp_active is not 0?
>
> Not at this point, in any testing I did.
> But I do not know the authoritative answer
> to your question.
>
But as you explained you want to prevent repeated print of
"HWP enabled by BIOS". So you need this.
> >
> > > && boot_cpu_has(X86_FEATURE_HWP))
> > > + if(intel_pstate_hwp_is_enabled()){
> > > + pr_info("HWP enabled by BIOS\n");
> > > + hwp_active = 1;
> > > + }
> > > if (!str)
> > > return -EINVAL;
> > >
> > > - if (!strcmp(str, "disable"))
> > > + if (!strcmp(str, "disable") && !hwp_active)
> > > no_load = 1;
> > > - else if (!strcmp(str, "active"))
> > > + if (!strcmp(str, "active"))
> > > default_driver = &intel_pstate;
> > > - else if (!strcmp(str, "passive"))
> > > + if (!strcmp(str, "passive"))
> > > default_driver = &intel_cpufreq;
> >
> > Why "else if" changed to "if" ?
>
> Because it doesn't matter anyway and I would
> have had to figure out another qualifier.
> This way, and given that this executes once per
> intel_pstate command line parameter, the code
> executes the way it used to, overall.
If someone specified intel_pstate=active, it will also compare with
"passive" with this change.
Thanks,
Srinivas
>
> >
> >
> > Thanks,
> > Srinivas
> >
> > > -
> > > - if (!strcmp(str, "no_hwp")) {
> > > + if (!strcmp(str, "no_hwp") && !hwp_active) {
> > > pr_info("HWP disabled\n");
> > > no_hwp = 1;
> > > }
> >
> >
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 13:20 ` Doug Smythies
@ 2021-09-09 16:12 ` Rafael J. Wysocki
2021-09-09 17:22 ` Rafael J. Wysocki
0 siblings, 1 reply; 13+ messages in thread
From: Rafael J. Wysocki @ 2021-09-09 16:12 UTC (permalink / raw)
To: Doug Smythies
Cc: Rafael J. Wysocki, Srinivas Pandruvada, Len Brown,
Linux Kernel Mailing List, Linux PM
On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote:
>
> On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> >
> > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
> > <srinivas.pandruvada@linux.intel.com> wrote:
> > >
> > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > > If HWP has been already been enabled by BIOS, it may be
> > > > necessary to override some kernel command line parameters.
> > > > Once it has been enabled it requires a reset to be disabled.
> > > >
> > > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > > ---
> > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > > b/drivers/cpufreq/intel_pstate.c
> > > > index bb4549959b11..073bae5d4498 100644
> > > > --- a/drivers/cpufreq/intel_pstate.c
> > > > +++ b/drivers/cpufreq/intel_pstate.c
> > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > > */
> > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > > intel_pstate_hwp_is_enabled()) {
> > > > - hwp_active++;
> > > > + hwp_active = 1;
> > > Why this change?
> >
> > I think hwp_active can be changed to bool and then it would make sense
> > to update this line.
> >
> > > > hwp_mode_bdw = id->driver_data;
> > > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > > >
> > > > static int __init intel_pstate_setup(char *str)
> > > > {
> > > > + /*
> > > > + * If BIOS is forcing HWP, then parameter
> > > > + * overrides might be needed. Only print
> > > > + * the message once, and regardless of
> > > > + * any overrides.
> > > > + */
> > > > + if(!hwp_active
> > > This part of code is from early_param, Is it possible that
> > > hwp_active is not 0?
> >
> > Well, it wouldn't matter even if it were nonzero. This check is just
> > pointless anyway.
> >
> > > > && boot_cpu_has(X86_FEATURE_HWP))
> > > > + if(intel_pstate_hwp_is_enabled()){
> >
> > This should be
> >
> > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
>
> Disagree.
> This routine gets executed once per intel_pstate related grub command
> line entry. The purpose of the "if(!hwp_active" part is to prevent the
> printing of the message to the logs multiple times.
Ah OK. Fair enough.
You can do all of the checks in one conditional, though. They will be
processed left-to-right anyway.
But then it would be good to avoid calling
intel_pstate_hwp_is_enabled() multiple times if it returns false.
And having said all that I'm not sure why you are trying to make
no_hwp depend on !hwp_active? I will not be taken into account anyway
if intel_pstate_hwp_is_enabled() returns 'true'?
So if no_hwp is covered regardless, you may move the
intel_pstate_hwp_is_enabled() inside the no_load conditional.
Alternatively, and I would do that, intel_pstate_hwp_is_enabled()
could be evaluated earlier in intel_pstate_init() and if it returned
'true', both no_load and no_hwp would be disregarded.
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 16:12 ` Rafael J. Wysocki
@ 2021-09-09 17:22 ` Rafael J. Wysocki
2021-09-10 3:14 ` Doug Smythies
0 siblings, 1 reply; 13+ messages in thread
From: Rafael J. Wysocki @ 2021-09-09 17:22 UTC (permalink / raw)
To: Doug Smythies
Cc: Rafael J. Wysocki, Srinivas Pandruvada, Len Brown,
Linux Kernel Mailing List, Linux PM
[-- Attachment #1: Type: text/plain, Size: 3686 bytes --]
On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote:
> >
> > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > >
> > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
> > > <srinivas.pandruvada@linux.intel.com> wrote:
> > > >
> > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > > > If HWP has been already been enabled by BIOS, it may be
> > > > > necessary to override some kernel command line parameters.
> > > > > Once it has been enabled it requires a reset to be disabled.
> > > > >
> > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > > > ---
> > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > > > >
> > > > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > > > b/drivers/cpufreq/intel_pstate.c
> > > > > index bb4549959b11..073bae5d4498 100644
> > > > > --- a/drivers/cpufreq/intel_pstate.c
> > > > > +++ b/drivers/cpufreq/intel_pstate.c
> > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > > > */
> > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > > > intel_pstate_hwp_is_enabled()) {
> > > > > - hwp_active++;
> > > > > + hwp_active = 1;
> > > > Why this change?
> > >
> > > I think hwp_active can be changed to bool and then it would make sense
> > > to update this line.
> > >
> > > > > hwp_mode_bdw = id->driver_data;
> > > > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > > > >
> > > > > static int __init intel_pstate_setup(char *str)
> > > > > {
> > > > > + /*
> > > > > + * If BIOS is forcing HWP, then parameter
> > > > > + * overrides might be needed. Only print
> > > > > + * the message once, and regardless of
> > > > > + * any overrides.
> > > > > + */
> > > > > + if(!hwp_active
> > > > This part of code is from early_param, Is it possible that
> > > > hwp_active is not 0?
> > >
> > > Well, it wouldn't matter even if it were nonzero. This check is just
> > > pointless anyway.
> > >
> > > > > && boot_cpu_has(X86_FEATURE_HWP))
> > > > > + if(intel_pstate_hwp_is_enabled()){
> > >
> > > This should be
> > >
> > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
> >
> > Disagree.
> > This routine gets executed once per intel_pstate related grub command
> > line entry. The purpose of the "if(!hwp_active" part is to prevent the
> > printing of the message to the logs multiple times.
>
> Ah OK. Fair enough.
>
> You can do all of the checks in one conditional, though. They will be
> processed left-to-right anyway.
>
> But then it would be good to avoid calling
> intel_pstate_hwp_is_enabled() multiple times if it returns false.
>
> And having said all that I'm not sure why you are trying to make
> no_hwp depend on !hwp_active? I will not be taken into account anyway
> if intel_pstate_hwp_is_enabled() returns 'true'?
>
> So if no_hwp is covered regardless, you may move the
> intel_pstate_hwp_is_enabled() inside the no_load conditional.
>
> Alternatively, and I would do that, intel_pstate_hwp_is_enabled()
> could be evaluated earlier in intel_pstate_init() and if it returned
> 'true', both no_load and no_hwp would be disregarded.
Something like the attached, for the record.
[-- Attachment #2: intel_pstate-arguments.patch --]
[-- Type: text/x-patch, Size: 1463 bytes --]
---
drivers/cpufreq/intel_pstate.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -3205,11 +3205,15 @@ static int __init intel_pstate_init(void
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return -ENODEV;
- if (no_load)
- return -ENODEV;
-
id = x86_match_cpu(hwp_support_ids);
if (id) {
+ bool hwp_forced = intel_pstate_hwp_is_enabled();
+
+ if (hwp_forced)
+ pr_info("HWP enabled by BIOS\n");
+ else if (no_load)
+ return -ENODEV;
+
copy_cpu_funcs(&core_funcs);
/*
* Avoid enabling HWP for processors without EPP support,
@@ -3219,8 +3223,7 @@ static int __init intel_pstate_init(void
* If HWP is enabled already, though, there is no choice but to
* deal with it.
*/
- if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
- intel_pstate_hwp_is_enabled()) {
+ if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) {
hwp_active++;
hwp_mode_bdw = id->driver_data;
intel_pstate.attr = hwp_cpufreq_attrs;
@@ -3236,6 +3239,9 @@ static int __init intel_pstate_init(void
goto hwp_cpu_matched;
}
} else {
+ if (no_load)
+ return -ENODEV;
+
id = x86_match_cpu(intel_pstate_cpu_ids);
if (!id) {
pr_info("CPU model not supported\n");
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 17:22 ` Rafael J. Wysocki
@ 2021-09-10 3:14 ` Doug Smythies
2021-09-10 11:18 ` Rafael J. Wysocki
0 siblings, 1 reply; 13+ messages in thread
From: Doug Smythies @ 2021-09-10 3:14 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Srinivas Pandruvada, Len Brown, Linux Kernel Mailing List,
Linux PM, dsmythies
On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote:
> > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
> > > > <srinivas.pandruvada@linux.intel.com> wrote:
> > > > >
> > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > > > > If HWP has been already been enabled by BIOS, it may be
> > > > > > necessary to override some kernel command line parameters.
> > > > > > Once it has been enabled it requires a reset to be disabled.
> > > > > >
> > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > > > > ---
> > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > > > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > > > > b/drivers/cpufreq/intel_pstate.c
> > > > > > index bb4549959b11..073bae5d4498 100644
> > > > > > --- a/drivers/cpufreq/intel_pstate.c
> > > > > > +++ b/drivers/cpufreq/intel_pstate.c
> > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > > > > */
> > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > > > > intel_pstate_hwp_is_enabled()) {
> > > > > > - hwp_active++;
> > > > > > + hwp_active = 1;
> > > > > Why this change?
> > > >
> > > > I think hwp_active can be changed to bool and then it would make sense
> > > > to update this line.
> > > >
> > > > > > hwp_mode_bdw = id->driver_data;
> > > > > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > > > > >
> > > > > > static int __init intel_pstate_setup(char *str)
> > > > > > {
> > > > > > + /*
> > > > > > + * If BIOS is forcing HWP, then parameter
> > > > > > + * overrides might be needed. Only print
> > > > > > + * the message once, and regardless of
> > > > > > + * any overrides.
> > > > > > + */
> > > > > > + if(!hwp_active
> > > > > This part of code is from early_param, Is it possible that
> > > > > hwp_active is not 0?
> > > >
> > > > Well, it wouldn't matter even if it were nonzero. This check is just
> > > > pointless anyway.
> > > >
> > > > > > && boot_cpu_has(X86_FEATURE_HWP))
> > > > > > + if(intel_pstate_hwp_is_enabled()){
> > > >
> > > > This should be
> > > >
> > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
> > >
> > > Disagree.
> > > This routine gets executed once per intel_pstate related grub command
> > > line entry. The purpose of the "if(!hwp_active" part is to prevent the
> > > printing of the message to the logs multiple times.
> >
> > Ah OK. Fair enough.
> >
> > You can do all of the checks in one conditional, though. They will be
> > processed left-to-right anyway.
> >
> > But then it would be good to avoid calling
> > intel_pstate_hwp_is_enabled() multiple times if it returns false.
> >
> > And having said all that I'm not sure why you are trying to make
> > no_hwp depend on !hwp_active? I will not be taken into account anyway
> > if intel_pstate_hwp_is_enabled() returns 'true'?
> >
> > So if no_hwp is covered regardless, you may move the
> > intel_pstate_hwp_is_enabled() inside the no_load conditional.
> >
> > Alternatively, and I would do that, intel_pstate_hwp_is_enabled()
> > could be evaluated earlier in intel_pstate_init() and if it returned
> > 'true', both no_load and no_hwp would be disregarded.
>
> Something like the attached, for the record.
O.K. and Thanks.
I was trying to avoid this line getting into the log:
[ 0.000000] intel_pstate: HWP disabled
only to overridden later by, now, these lines:
[ 0.373742] intel_pstate: HWP enabled by BIOS
[ 0.374177] intel_pstate: Intel P-state driver initializing
[ 0.375097] intel_pstate: HWP enabled
Let me see if I can go with your suggestion and get to
what I had hoped to get in the logs.
By the way, my current command line options are:
[ 0.000000] Command line:
BOOT_IMAGE=/boot/vmlinuz-5.14.0-ipstate9
root=UUID=0ac356c1-caa9-4c2e-8229-4408bd998dbd
ro ipv6.disable=1 consoleblank=314 intel_pstate=force
intel_pstate=active intel_pstate=no_hwp
msr.allow_writes=on cpuidle.governor=teo
... Doug
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-09 14:52 ` Srinivas Pandruvada
@ 2021-09-10 4:11 ` Doug Smythies
0 siblings, 0 replies; 13+ messages in thread
From: Doug Smythies @ 2021-09-10 4:11 UTC (permalink / raw)
To: Srinivas Pandruvada
Cc: Rafael J. Wysocki, Len Brown, Linux Kernel Mailing List,
Linux PM list, dsmythies
On Thu, Sep 9, 2021 at 7:53 AM Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
> On Thu, 2021-09-09 at 06:30 -0700, Doug Smythies wrote:
> > On Wed, Sep 8, 2021 at 11:33 PM Srinivas Pandruvada
> > <srinivas.pandruvada@linux.intel.com> wrote:
> > >
> > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > > If HWP has been already been enabled by BIOS, it may be
> > > > necessary to override some kernel command line parameters.
> > > > Once it has been enabled it requires a reset to be disabled.
> > > >
> > > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > > ---
> > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > > b/drivers/cpufreq/intel_pstate.c
> > > > index bb4549959b11..073bae5d4498 100644
> > > > --- a/drivers/cpufreq/intel_pstate.c
> > > > +++ b/drivers/cpufreq/intel_pstate.c
> > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > > */
> > > > if ((!no_hwp &&
> > > > boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > > intel_pstate_hwp_is_enabled()) {
> > > > - hwp_active++;
> > > > + hwp_active = 1;
> > > Why this change?
> >
> > It was just to keep it at 1, but I agree not absolutely needed.
> >
> > >
> > > > hwp_mode_bdw = id->driver_data;
> > > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > > >
> > > > static int __init intel_pstate_setup(char *str)
> > > > {
> > > > + /*
> > > > + * If BIOS is forcing HWP, then parameter
> > > > + * overrides might be needed. Only print
> > > > + * the message once, and regardless of
> > > > + * any overrides.
> > > > + */
> > > > + if(!hwp_active
> > > This part of code is from early_param, Is it possible that
> > > hwp_active is not 0?
> >
> > Not at this point, in any testing I did.
> > But I do not know the authoritative answer
> > to your question.
> >
> But as you explained you want to prevent repeated print of
> "HWP enabled by BIOS". So you need this.
>
> > >
> > > > && boot_cpu_has(X86_FEATURE_HWP))
> > > > + if(intel_pstate_hwp_is_enabled()){
> > > > + pr_info("HWP enabled by BIOS\n");
> > > > + hwp_active = 1;
> > > > + }
> > > > if (!str)
> > > > return -EINVAL;
> > > >
> > > > - if (!strcmp(str, "disable"))
> > > > + if (!strcmp(str, "disable") && !hwp_active)
> > > > no_load = 1;
> > > > - else if (!strcmp(str, "active"))
> > > > + if (!strcmp(str, "active"))
> > > > default_driver = &intel_pstate;
> > > > - else if (!strcmp(str, "passive"))
> > > > + if (!strcmp(str, "passive"))
> > > > default_driver = &intel_cpufreq;
> > >
> > > Why "else if" changed to "if" ?
> >
> > Because it doesn't matter anyway and I would
> > have had to figure out another qualifier.
> > This way, and given that this executes once per
> > intel_pstate command line parameter, the code
> > executes the way it used to, overall.
> If someone specified intel_pstate=active, it will also compare with
> "passive" with this change.
Disagree.
As far as I can tell, and I tested, it works as expected.
... Doug
> > > > -
> > > > - if (!strcmp(str, "no_hwp")) {
> > > > + if (!strcmp(str, "no_hwp") && !hwp_active) {
> > > > pr_info("HWP disabled\n");
> > > > no_hwp = 1;
> > > > }
> > >
> > >
>
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-10 3:14 ` Doug Smythies
@ 2021-09-10 11:18 ` Rafael J. Wysocki
2021-09-10 15:34 ` Doug Smythies
0 siblings, 1 reply; 13+ messages in thread
From: Rafael J. Wysocki @ 2021-09-10 11:18 UTC (permalink / raw)
To: Doug Smythies
Cc: Rafael J. Wysocki, Srinivas Pandruvada, Len Brown,
Linux Kernel Mailing List, Linux PM
[-- Attachment #1: Type: text/plain, Size: 4830 bytes --]
On Fri, Sep 10, 2021 at 5:14 AM Doug Smythies <dsmythies@telus.net> wrote:
>
> On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote:
> > > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
> > > > > <srinivas.pandruvada@linux.intel.com> wrote:
> > > > > >
> > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > > > > > If HWP has been already been enabled by BIOS, it may be
> > > > > > > necessary to override some kernel command line parameters.
> > > > > > > Once it has been enabled it requires a reset to be disabled.
> > > > > > >
> > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > > > > > ---
> > > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > > > > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > > > > > >
> > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > > > > > b/drivers/cpufreq/intel_pstate.c
> > > > > > > index bb4549959b11..073bae5d4498 100644
> > > > > > > --- a/drivers/cpufreq/intel_pstate.c
> > > > > > > +++ b/drivers/cpufreq/intel_pstate.c
> > > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > > > > > */
> > > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > > > > > intel_pstate_hwp_is_enabled()) {
> > > > > > > - hwp_active++;
> > > > > > > + hwp_active = 1;
> > > > > > Why this change?
> > > > >
> > > > > I think hwp_active can be changed to bool and then it would make sense
> > > > > to update this line.
> > > > >
> > > > > > > hwp_mode_bdw = id->driver_data;
> > > > > > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > > > > > >
> > > > > > > static int __init intel_pstate_setup(char *str)
> > > > > > > {
> > > > > > > + /*
> > > > > > > + * If BIOS is forcing HWP, then parameter
> > > > > > > + * overrides might be needed. Only print
> > > > > > > + * the message once, and regardless of
> > > > > > > + * any overrides.
> > > > > > > + */
> > > > > > > + if(!hwp_active
> > > > > > This part of code is from early_param, Is it possible that
> > > > > > hwp_active is not 0?
> > > > >
> > > > > Well, it wouldn't matter even if it were nonzero. This check is just
> > > > > pointless anyway.
> > > > >
> > > > > > > && boot_cpu_has(X86_FEATURE_HWP))
> > > > > > > + if(intel_pstate_hwp_is_enabled()){
> > > > >
> > > > > This should be
> > > > >
> > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
> > > >
> > > > Disagree.
> > > > This routine gets executed once per intel_pstate related grub command
> > > > line entry. The purpose of the "if(!hwp_active" part is to prevent the
> > > > printing of the message to the logs multiple times.
> > >
> > > Ah OK. Fair enough.
> > >
> > > You can do all of the checks in one conditional, though. They will be
> > > processed left-to-right anyway.
> > >
> > > But then it would be good to avoid calling
> > > intel_pstate_hwp_is_enabled() multiple times if it returns false.
> > >
> > > And having said all that I'm not sure why you are trying to make
> > > no_hwp depend on !hwp_active? I will not be taken into account anyway
> > > if intel_pstate_hwp_is_enabled() returns 'true'?
> > >
> > > So if no_hwp is covered regardless, you may move the
> > > intel_pstate_hwp_is_enabled() inside the no_load conditional.
> > >
> > > Alternatively, and I would do that, intel_pstate_hwp_is_enabled()
> > > could be evaluated earlier in intel_pstate_init() and if it returned
> > > 'true', both no_load and no_hwp would be disregarded.
> >
> > Something like the attached, for the record.
>
> O.K. and Thanks.
> I was trying to avoid this line getting into the log:
>
> [ 0.000000] intel_pstate: HWP disabled
>
> only to overridden later by, now, these lines:
>
> [ 0.373742] intel_pstate: HWP enabled by BIOS
> [ 0.374177] intel_pstate: Intel P-state driver initializing
> [ 0.375097] intel_pstate: HWP enabled
>
> Let me see if I can go with your suggestion and get to
> what I had hoped to get in the logs.
It would be sufficient to put the "disabled" printk() after the
"no_hwp" if () statement in intel_pstate_init(). See attached.
BTW, I've changed the message to "HWP not enabled", because that's
what really happens to be precise.
[-- Attachment #2: intel_pstate-arguments.patch --]
[-- Type: text/x-patch, Size: 1836 bytes --]
---
drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -3205,11 +3205,15 @@ static int __init intel_pstate_init(void
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return -ENODEV;
- if (no_load)
- return -ENODEV;
-
id = x86_match_cpu(hwp_support_ids);
if (id) {
+ bool hwp_forced = intel_pstate_hwp_is_enabled();
+
+ if (hwp_forced)
+ pr_info("HWP enabled by BIOS\n");
+ else if (no_load)
+ return -ENODEV;
+
copy_cpu_funcs(&core_funcs);
/*
* Avoid enabling HWP for processors without EPP support,
@@ -3219,8 +3223,7 @@ static int __init intel_pstate_init(void
* If HWP is enabled already, though, there is no choice but to
* deal with it.
*/
- if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
- intel_pstate_hwp_is_enabled()) {
+ if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) {
hwp_active++;
hwp_mode_bdw = id->driver_data;
intel_pstate.attr = hwp_cpufreq_attrs;
@@ -3235,7 +3238,11 @@ static int __init intel_pstate_init(void
goto hwp_cpu_matched;
}
+ pr_info("HWP not enabled\n");
} else {
+ if (no_load)
+ return -ENODEV;
+
id = x86_match_cpu(intel_pstate_cpu_ids);
if (!id) {
pr_info("CPU model not supported\n");
@@ -3314,10 +3321,9 @@ static int __init intel_pstate_setup(cha
else if (!strcmp(str, "passive"))
default_driver = &intel_cpufreq;
- if (!strcmp(str, "no_hwp")) {
- pr_info("HWP disabled\n");
+ if (!strcmp(str, "no_hwp"))
no_hwp = 1;
- }
+
if (!strcmp(str, "force"))
force_load = 1;
if (!strcmp(str, "hwp_only"))
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-10 11:18 ` Rafael J. Wysocki
@ 2021-09-10 15:34 ` Doug Smythies
2021-09-10 15:45 ` Rafael J. Wysocki
0 siblings, 1 reply; 13+ messages in thread
From: Doug Smythies @ 2021-09-10 15:34 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Srinivas Pandruvada, Len Brown, Linux Kernel Mailing List,
Linux PM, dsmythies
On Fri, Sep 10, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> On Fri, Sep 10, 2021 at 5:14 AM Doug Smythies <dsmythies@telus.net> wrote:
> > On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote:
> > > > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
> > > > > > <srinivas.pandruvada@linux.intel.com> wrote:
> > > > > > >
> > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > > > > > > If HWP has been already been enabled by BIOS, it may be
> > > > > > > > necessary to override some kernel command line parameters.
> > > > > > > > Once it has been enabled it requires a reset to be disabled.
> > > > > > > >
> > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > > > > > > ---
> > > > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > > > > > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > > > > > > b/drivers/cpufreq/intel_pstate.c
> > > > > > > > index bb4549959b11..073bae5d4498 100644
> > > > > > > > --- a/drivers/cpufreq/intel_pstate.c
> > > > > > > > +++ b/drivers/cpufreq/intel_pstate.c
> > > > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > > > > > > */
> > > > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > > > > > > intel_pstate_hwp_is_enabled()) {
> > > > > > > > - hwp_active++;
> > > > > > > > + hwp_active = 1;
> > > > > > > Why this change?
> > > > > >
> > > > > > I think hwp_active can be changed to bool and then it would make sense
> > > > > > to update this line.
> > > > > >
> > > > > > > > hwp_mode_bdw = id->driver_data;
> > > > > > > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > > > > > > >
> > > > > > > > static int __init intel_pstate_setup(char *str)
> > > > > > > > {
> > > > > > > > + /*
> > > > > > > > + * If BIOS is forcing HWP, then parameter
> > > > > > > > + * overrides might be needed. Only print
> > > > > > > > + * the message once, and regardless of
> > > > > > > > + * any overrides.
> > > > > > > > + */
> > > > > > > > + if(!hwp_active
> > > > > > > This part of code is from early_param, Is it possible that
> > > > > > > hwp_active is not 0?
> > > > > >
> > > > > > Well, it wouldn't matter even if it were nonzero. This check is just
> > > > > > pointless anyway.
> > > > > >
> > > > > > > > && boot_cpu_has(X86_FEATURE_HWP))
> > > > > > > > + if(intel_pstate_hwp_is_enabled()){
> > > > > >
> > > > > > This should be
> > > > > >
> > > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
> > > > >
> > > > > Disagree.
> > > > > This routine gets executed once per intel_pstate related grub command
> > > > > line entry. The purpose of the "if(!hwp_active" part is to prevent the
> > > > > printing of the message to the logs multiple times.
> > > >
> > > > Ah OK. Fair enough.
> > > >
> > > > You can do all of the checks in one conditional, though. They will be
> > > > processed left-to-right anyway.
> > > >
> > > > But then it would be good to avoid calling
> > > > intel_pstate_hwp_is_enabled() multiple times if it returns false.
> > > >
> > > > And having said all that I'm not sure why you are trying to make
> > > > no_hwp depend on !hwp_active? I will not be taken into account anyway
> > > > if intel_pstate_hwp_is_enabled() returns 'true'?
> > > >
> > > > So if no_hwp is covered regardless, you may move the
> > > > intel_pstate_hwp_is_enabled() inside the no_load conditional.
> > > >
> > > > Alternatively, and I would do that, intel_pstate_hwp_is_enabled()
> > > > could be evaluated earlier in intel_pstate_init() and if it returned
> > > > 'true', both no_load and no_hwp would be disregarded.
> > >
> > > Something like the attached, for the record.
> >
> > O.K. and Thanks.
> > I was trying to avoid this line getting into the log:
> >
> > [ 0.000000] intel_pstate: HWP disabled
> >
> > only to overridden later by, now, these lines:
> >
> > [ 0.373742] intel_pstate: HWP enabled by BIOS
> > [ 0.374177] intel_pstate: Intel P-state driver initializing
> > [ 0.375097] intel_pstate: HWP enabled
> >
> > Let me see if I can go with your suggestion and get to
> > what I had hoped to get in the logs.
>
> It would be sufficient to put the "disabled" printk() after the
> "no_hwp" if () statement in intel_pstate_init(). See attached.
Agreed, thanks. Yes, I was thinking similar.
> BTW, I've changed the message to "HWP not enabled", because that's
> what really happens to be precise.
Agreed. Good idea.
Give me a fews days to create and test a formal patch.
I currently have limited access to a computer that doesn't force
HWP via BIOS.
... Doug
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS
2021-09-10 15:34 ` Doug Smythies
@ 2021-09-10 15:45 ` Rafael J. Wysocki
0 siblings, 0 replies; 13+ messages in thread
From: Rafael J. Wysocki @ 2021-09-10 15:45 UTC (permalink / raw)
To: Doug Smythies
Cc: Rafael J. Wysocki, Srinivas Pandruvada, Len Brown,
Linux Kernel Mailing List, Linux PM
On Fri, Sep 10, 2021 at 5:35 PM Doug Smythies <dsmythies@telus.net> wrote:
>
> On Fri, Sep 10, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > On Fri, Sep 10, 2021 at 5:14 AM Doug Smythies <dsmythies@telus.net> wrote:
> > > On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote:
> > > > > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada
> > > > > > > <srinivas.pandruvada@linux.intel.com> wrote:
> > > > > > > >
> > > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote:
> > > > > > > > > If HWP has been already been enabled by BIOS, it may be
> > > > > > > > > necessary to override some kernel command line parameters.
> > > > > > > > > Once it has been enabled it requires a reset to be disabled.
> > > > > > > > >
> > > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net>
> > > > > > > > > ---
> > > > > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------
> > > > > > > > > 1 file changed, 16 insertions(+), 6 deletions(-)
> > > > > > > > >
> > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c
> > > > > > > > > b/drivers/cpufreq/intel_pstate.c
> > > > > > > > > index bb4549959b11..073bae5d4498 100644
> > > > > > > > > --- a/drivers/cpufreq/intel_pstate.c
> > > > > > > > > +++ b/drivers/cpufreq/intel_pstate.c
> > > > > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void)
> > > > > > > > > */
> > > > > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
> > > > > > > > > intel_pstate_hwp_is_enabled()) {
> > > > > > > > > - hwp_active++;
> > > > > > > > > + hwp_active = 1;
> > > > > > > > Why this change?
> > > > > > >
> > > > > > > I think hwp_active can be changed to bool and then it would make sense
> > > > > > > to update this line.
> > > > > > >
> > > > > > > > > hwp_mode_bdw = id->driver_data;
> > > > > > > > > intel_pstate.attr = hwp_cpufreq_attrs;
> > > > > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs;
> > > > > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init);
> > > > > > > > >
> > > > > > > > > static int __init intel_pstate_setup(char *str)
> > > > > > > > > {
> > > > > > > > > + /*
> > > > > > > > > + * If BIOS is forcing HWP, then parameter
> > > > > > > > > + * overrides might be needed. Only print
> > > > > > > > > + * the message once, and regardless of
> > > > > > > > > + * any overrides.
> > > > > > > > > + */
> > > > > > > > > + if(!hwp_active
> > > > > > > > This part of code is from early_param, Is it possible that
> > > > > > > > hwp_active is not 0?
> > > > > > >
> > > > > > > Well, it wouldn't matter even if it were nonzero. This check is just
> > > > > > > pointless anyway.
> > > > > > >
> > > > > > > > > && boot_cpu_has(X86_FEATURE_HWP))
> > > > > > > > > + if(intel_pstate_hwp_is_enabled()){
> > > > > > >
> > > > > > > This should be
> > > > > > >
> > > > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) {
> > > > > >
> > > > > > Disagree.
> > > > > > This routine gets executed once per intel_pstate related grub command
> > > > > > line entry. The purpose of the "if(!hwp_active" part is to prevent the
> > > > > > printing of the message to the logs multiple times.
> > > > >
> > > > > Ah OK. Fair enough.
> > > > >
> > > > > You can do all of the checks in one conditional, though. They will be
> > > > > processed left-to-right anyway.
> > > > >
> > > > > But then it would be good to avoid calling
> > > > > intel_pstate_hwp_is_enabled() multiple times if it returns false.
> > > > >
> > > > > And having said all that I'm not sure why you are trying to make
> > > > > no_hwp depend on !hwp_active? I will not be taken into account anyway
> > > > > if intel_pstate_hwp_is_enabled() returns 'true'?
> > > > >
> > > > > So if no_hwp is covered regardless, you may move the
> > > > > intel_pstate_hwp_is_enabled() inside the no_load conditional.
> > > > >
> > > > > Alternatively, and I would do that, intel_pstate_hwp_is_enabled()
> > > > > could be evaluated earlier in intel_pstate_init() and if it returned
> > > > > 'true', both no_load and no_hwp would be disregarded.
> > > >
> > > > Something like the attached, for the record.
> > >
> > > O.K. and Thanks.
> > > I was trying to avoid this line getting into the log:
> > >
> > > [ 0.000000] intel_pstate: HWP disabled
> > >
> > > only to overridden later by, now, these lines:
> > >
> > > [ 0.373742] intel_pstate: HWP enabled by BIOS
> > > [ 0.374177] intel_pstate: Intel P-state driver initializing
> > > [ 0.375097] intel_pstate: HWP enabled
> > >
> > > Let me see if I can go with your suggestion and get to
> > > what I had hoped to get in the logs.
> >
> > It would be sufficient to put the "disabled" printk() after the
> > "no_hwp" if () statement in intel_pstate_init(). See attached.
>
> Agreed, thanks. Yes, I was thinking similar.
>
> > BTW, I've changed the message to "HWP not enabled", because that's
> > what really happens to be precise.
>
> Agreed. Good idea.
>
> Give me a fews days to create and test a formal patch.
OK
> I currently have limited access to a computer that doesn't force
> HWP via BIOS.
^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2021-09-10 15:45 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-09 3:48 [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS Doug Smythies
2021-09-09 6:33 ` Srinivas Pandruvada
2021-09-09 11:18 ` Rafael J. Wysocki
2021-09-09 13:20 ` Doug Smythies
2021-09-09 16:12 ` Rafael J. Wysocki
2021-09-09 17:22 ` Rafael J. Wysocki
2021-09-10 3:14 ` Doug Smythies
2021-09-10 11:18 ` Rafael J. Wysocki
2021-09-10 15:34 ` Doug Smythies
2021-09-10 15:45 ` Rafael J. Wysocki
2021-09-09 13:30 ` Doug Smythies
2021-09-09 14:52 ` Srinivas Pandruvada
2021-09-10 4:11 ` Doug Smythies
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).