[PATCH 07/11] platform/x86/intel/pmc: Alder Lake slp_s0_residency fix

David E. Box
2023-03-15T18:34:39Z

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)
--
2.34.1