[PATCH] platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

[PATCH] platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

[David E. Box]

From: Rajvi Jingar <rajvi.jingar@linux.intel.com>

For platforms with Alder Lake PCH (Alder Lake S and Raptor Lake S) the
slp_s0_residency attribute has been reporting the wrong value. Unlike other
platforms, ADL PCH does not have a counter for the time that the SLP_S0
signal was asserted. Instead, firmware uses the aggregate of the Low Power
Mode (LPM) substate counters as the S0ix value.  Since the LPM counters run
at a different frequency, this lead to misreporting of the S0ix time.

Add a check for Alder Lake PCH and adjust the frequency accordingly when
display slp_s0_residency.

Fixes: bbab31101f44 ("platform/x86/intel: pmc/core: Add Alderlake support to pmc core driver")
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
 drivers/platform/x86/intel/pmc/core.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index e489d2175e42..61ca7c37fb02 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -66,7 +66,18 @@ static inline void pmc_core_reg_write(struct pmc_dev *pmcdev, int reg_offset,
 
 static inline u64 pmc_core_adjust_slp_s0_step(struct pmc_dev *pmcdev, u32 value)
 {
-	return (u64)value * pmcdev->map->slp_s0_res_counter_step;
+	/*
+	 * ADL PCH does not have the SLP_S0 counter and LPM Residency counters are
+	 * used as a workaround which uses 30.5 usec tick. All other client
+	 * programs have the legacy SLP_S0 residency counter that is using the 122
+	 * usec tick.
+	 */
+	const int lpm_adj_x2 = pmcdev->map->lpm_res_counter_step_x2;
+
+	if (pmcdev->map == &adl_reg_map)
+		return (u64)value * GET_X2_COUNTER((u64)lpm_adj_x2);
+	else
+		return (u64)value * pmcdev->map->slp_s0_res_counter_step;
 }
 
 static int set_etr3(struct pmc_dev *pmcdev)

base-commit: 02c464b73645404654359ad21f368a13735e2850
-- 
2.34.1

Re: [PATCH] platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

[Rajneesh Bhardwaj]

Looks good to me.  Just a nit, maybe change the subject to "Fix Alder
Lake S0ix reporting" or something like that.

Reviewed-by: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>

On Mon, Mar 20, 2023 at 5:20 PM David E. Box
<david.e.box@linux.intel.com> wrote:
>
> From: Rajvi Jingar <rajvi.jingar@linux.intel.com>
>
> For platforms with Alder Lake PCH (Alder Lake S and Raptor Lake S) the
> slp_s0_residency attribute has been reporting the wrong value. Unlike other
> platforms, ADL PCH does not have a counter for the time that the SLP_S0
> signal was asserted. Instead, firmware uses the aggregate of the Low Power
> Mode (LPM) substate counters as the S0ix value.  Since the LPM counters run
> at a different frequency, this lead to misreporting of the S0ix time.
>
> Add a check for Alder Lake PCH and adjust the frequency accordingly when
> display slp_s0_residency.
>
> Fixes: bbab31101f44 ("platform/x86/intel: pmc/core: Add Alderlake support to pmc core driver")
> Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
>  drivers/platform/x86/intel/pmc/core.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index e489d2175e42..61ca7c37fb02 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -66,7 +66,18 @@ static inline void pmc_core_reg_write(struct pmc_dev *pmcdev, int reg_offset,
>
>  static inline u64 pmc_core_adjust_slp_s0_step(struct pmc_dev *pmcdev, u32 value)
>  {
> -       return (u64)value * pmcdev->map->slp_s0_res_counter_step;
> +       /*
> +        * ADL PCH does not have the SLP_S0 counter and LPM Residency counters are
> +        * used as a workaround which uses 30.5 usec tick. All other client
> +        * programs have the legacy SLP_S0 residency counter that is using the 122
> +        * usec tick.
> +        */
> +       const int lpm_adj_x2 = pmcdev->map->lpm_res_counter_step_x2;
> +
> +       if (pmcdev->map == &adl_reg_map)
> +               return (u64)value * GET_X2_COUNTER((u64)lpm_adj_x2);
> +       else
> +               return (u64)value * pmcdev->map->slp_s0_res_counter_step;
>  }
>
>  static int set_etr3(struct pmc_dev *pmcdev)
>
> base-commit: 02c464b73645404654359ad21f368a13735e2850
> --
> 2.34.1
>


-- 
Thanks,
Rajneesh

Re: [PATCH] platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

[Andy Shevchenko]

On Mon, Mar 20, 2023 at 11:20 PM David E. Box
<david.e.box@linux.intel.com> wrote:
>
> From: Rajvi Jingar <rajvi.jingar@linux.intel.com>
>
> For platforms with Alder Lake PCH (Alder Lake S and Raptor Lake S) the
> slp_s0_residency attribute has been reporting the wrong value. Unlike other
> platforms, ADL PCH does not have a counter for the time that the SLP_S0
> signal was asserted. Instead, firmware uses the aggregate of the Low Power
> Mode (LPM) substate counters as the S0ix value.  Since the LPM counters run
> at a different frequency, this lead to misreporting of the S0ix time.
>
> Add a check for Alder Lake PCH and adjust the frequency accordingly when
> display slp_s0_residency.

OK!
But one nit-pick below.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Fixes: bbab31101f44 ("platform/x86/intel: pmc/core: Add Alderlake support to pmc core driver")
> Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
>  drivers/platform/x86/intel/pmc/core.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index e489d2175e42..61ca7c37fb02 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -66,7 +66,18 @@ static inline void pmc_core_reg_write(struct pmc_dev *pmcdev, int reg_offset,
>
>  static inline u64 pmc_core_adjust_slp_s0_step(struct pmc_dev *pmcdev, u32 value)
>  {
> -       return (u64)value * pmcdev->map->slp_s0_res_counter_step;
> +       /*
> +        * ADL PCH does not have the SLP_S0 counter and LPM Residency counters are
> +        * used as a workaround which uses 30.5 usec tick. All other client

microsecond or us or  µs (I prefer the latter).

> +        * programs have the legacy SLP_S0 residency counter that is using the 122
> +        * usec tick.

microsecond or us or µs (I prefer the latter).

> +        */
> +       const int lpm_adj_x2 = pmcdev->map->lpm_res_counter_step_x2;
> +
> +       if (pmcdev->map == &adl_reg_map)
> +               return (u64)value * GET_X2_COUNTER((u64)lpm_adj_x2);

> +       else

Redundant 'else'.

> +               return (u64)value * pmcdev->map->slp_s0_res_counter_step;
>  }
>
>  static int set_etr3(struct pmc_dev *pmcdev)
>
> base-commit: 02c464b73645404654359ad21f368a13735e2850
> --
> 2.34.1
>


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

[Hans de Goede]

Hi,

On 3/20/23 22:20, David E. Box wrote:
> From: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> 
> For platforms with Alder Lake PCH (Alder Lake S and Raptor Lake S) the
> slp_s0_residency attribute has been reporting the wrong value. Unlike other
> platforms, ADL PCH does not have a counter for the time that the SLP_S0
> signal was asserted. Instead, firmware uses the aggregate of the Low Power
> Mode (LPM) substate counters as the S0ix value.  Since the LPM counters run
> at a different frequency, this lead to misreporting of the S0ix time.
> 
> Add a check for Alder Lake PCH and adjust the frequency accordingly when
> display slp_s0_residency.
> 
> Fixes: bbab31101f44 ("platform/x86/intel: pmc/core: Add Alderlake support to pmc core driver")
> Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>

Thank you for your patch, I've applied this patch to my fixes
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=fixes

Note it will show up in my fixes branch once I've pushed my
local branch there, which might take a while.

I will include this patch in my next fixes pull-req to Linus
for the current kernel development cycle.

Regards,

Hans


> ---
>  drivers/platform/x86/intel/pmc/core.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index e489d2175e42..61ca7c37fb02 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -66,7 +66,18 @@ static inline void pmc_core_reg_write(struct pmc_dev *pmcdev, int reg_offset,
>  
>  static inline u64 pmc_core_adjust_slp_s0_step(struct pmc_dev *pmcdev, u32 value)
>  {
> -	return (u64)value * pmcdev->map->slp_s0_res_counter_step;
> +	/*
> +	 * ADL PCH does not have the SLP_S0 counter and LPM Residency counters are
> +	 * used as a workaround which uses 30.5 usec tick. All other client
> +	 * programs have the legacy SLP_S0 residency counter that is using the 122
> +	 * usec tick.
> +	 */
> +	const int lpm_adj_x2 = pmcdev->map->lpm_res_counter_step_x2;
> +
> +	if (pmcdev->map == &adl_reg_map)
> +		return (u64)value * GET_X2_COUNTER((u64)lpm_adj_x2);
> +	else
> +		return (u64)value * pmcdev->map->slp_s0_res_counter_step;
>  }
>  
>  static int set_etr3(struct pmc_dev *pmcdev)
> 
> base-commit: 02c464b73645404654359ad21f368a13735e2850