* [PATCH] cpufreq: intel_pstate: Fix processing for turbo activation ratio
@ 2016-04-23 2:53 Srinivas Pandruvada
2016-04-25 13:48 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Srinivas Pandruvada @ 2016-04-23 2:53 UTC (permalink / raw)
To: rjw; +Cc: linux-pm, Srinivas Pandruvada
When the config TDP level is not nominal (level = 0), the MSR values for
reading level 1 and level 2 ratios contain power in low 14 bits and actual
ratio bits are at bits [23:16]. The current processing for level 1 and
level 2 is wrong as there is no shift done to get actual ratio.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
drivers/cpufreq/intel_pstate.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1b2767d..03f94c2 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -813,6 +813,10 @@ static int core_get_max_pstate(void)
if (err)
goto skip_tar;
+ /* For level 1 and 2, bits[23:16] contains ratio */
+ if (tdp_ctrl)
+ tdp_ratio >>= 16;
+ tdp_ratio &= 0xff; /* ratios are only 8 bits long */
if (tdp_ratio - 1 == tar) {
max_pstate = tar;
pr_debug("max_pstate=TAC %x\n", max_pstate);
--
2.5.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Fix processing for turbo activation ratio
2016-04-23 2:53 [PATCH] cpufreq: intel_pstate: Fix processing for turbo activation ratio Srinivas Pandruvada
@ 2016-04-25 13:48 ` Rafael J. Wysocki
2016-04-25 16:28 ` Srinivas Pandruvada
0 siblings, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki @ 2016-04-25 13:48 UTC (permalink / raw)
To: Srinivas Pandruvada; +Cc: Rafael J. Wysocki, linux-pm
On Sat, Apr 23, 2016 at 4:53 AM, Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
> When the config TDP level is not nominal (level = 0), the MSR values for
> reading level 1 and level 2 ratios contain power in low 14 bits and actual
> ratio bits are at bits [23:16]. The current processing for level 1 and
> level 2 is wrong as there is no shift done to get actual ratio.
>
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Since this is a fix, do we need it in v4.6?
Do we want it in -stable too and in what -stable if so?
> ---
> drivers/cpufreq/intel_pstate.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 1b2767d..03f94c2 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -813,6 +813,10 @@ static int core_get_max_pstate(void)
> if (err)
> goto skip_tar;
>
> + /* For level 1 and 2, bits[23:16] contains ratio */
> + if (tdp_ctrl)
> + tdp_ratio >>= 16;
> + tdp_ratio &= 0xff; /* ratios are only 8 bits long */
> if (tdp_ratio - 1 == tar) {
> max_pstate = tar;
> pr_debug("max_pstate=TAC %x\n", max_pstate);
> --
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Fix processing for turbo activation ratio
2016-04-25 13:48 ` Rafael J. Wysocki
@ 2016-04-25 16:28 ` Srinivas Pandruvada
2016-04-25 21:44 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Srinivas Pandruvada @ 2016-04-25 16:28 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: Rafael J. Wysocki, linux-pm
On Mon, 2016-04-25 at 15:48 +0200, Rafael J. Wysocki wrote:
> On Sat, Apr 23, 2016 at 4:53 AM, Srinivas Pandruvada
> <srinivas.pandruvada@linux.intel.com> wrote:
> >
> > When the config TDP level is not nominal (level = 0), the MSR
> > values for
> > reading level 1 and level 2 ratios contain power in low 14 bits and
> > actual
> > ratio bits are at bits [23:16]. The current processing for level 1
> > and
> > level 2 is wrong as there is no shift done to get actual ratio.
> >
> > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel
> > .com>
> Since this is a fix, do we need it in v4.6?
>
This impact the display of turbo_pct in Intel P-state sysfs. So if not
too late, I prefer for v4.6.
> Do we want it in -stable too and in what -stable if so?
4.4 onward.
>
Thanks,
Srinivas
>
> >
> > ---
> > drivers/cpufreq/intel_pstate.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/cpufreq/intel_pstate.c
> > b/drivers/cpufreq/intel_pstate.c
> > index 1b2767d..03f94c2 100644
> > --- a/drivers/cpufreq/intel_pstate.c
> > +++ b/drivers/cpufreq/intel_pstate.c
> > @@ -813,6 +813,10 @@ static int core_get_max_pstate(void)
> > if (err)
> > goto skip_tar;
> >
> > + /* For level 1 and 2, bits[23:16] contains
> > ratio */
> > + if (tdp_ctrl)
> > + tdp_ratio >>= 16;
> > + tdp_ratio &= 0xff; /* ratios are only 8
> > bits long */
> > if (tdp_ratio - 1 == tar) {
> > max_pstate = tar;
> > pr_debug("max_pstate=TAC %x\n",
> > max_pstate);
> > --
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] cpufreq: intel_pstate: Fix processing for turbo activation ratio
2016-04-25 16:28 ` Srinivas Pandruvada
@ 2016-04-25 21:44 ` Rafael J. Wysocki
0 siblings, 0 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2016-04-25 21:44 UTC (permalink / raw)
To: Srinivas Pandruvada; +Cc: Rafael J. Wysocki, Rafael J. Wysocki, linux-pm
On Mon, Apr 25, 2016 at 6:28 PM, Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
> On Mon, 2016-04-25 at 15:48 +0200, Rafael J. Wysocki wrote:
>> On Sat, Apr 23, 2016 at 4:53 AM, Srinivas Pandruvada
>> <srinivas.pandruvada@linux.intel.com> wrote:
>> >
>> > When the config TDP level is not nominal (level = 0), the MSR
>> > values for
>> > reading level 1 and level 2 ratios contain power in low 14 bits and
>> > actual
>> > ratio bits are at bits [23:16]. The current processing for level 1
>> > and
>> > level 2 is wrong as there is no shift done to get actual ratio.
>> >
>> > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel
>> > .com>
>> Since this is a fix, do we need it in v4.6?
>>
> This impact the display of turbo_pct in Intel P-state sysfs. So if not
> too late, I prefer for v4.6.
>
>> Do we want it in -stable too and in what -stable if so?
> 4.4 onward.
OK
I also added a Fixes: tag to the commit.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-04-25 21:44 UTC | newest]
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2016-04-23 2:53 [PATCH] cpufreq: intel_pstate: Fix processing for turbo activation ratio Srinivas Pandruvada
2016-04-25 13:48 ` Rafael J. Wysocki
2016-04-25 16:28 ` Srinivas Pandruvada
2016-04-25 21:44 ` Rafael J. Wysocki
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