platform/x86/intel/pmc: Move GBE LTR ignore to suspend callback

Commit 804951203aa5 ("platform/x86:intel/pmc: Combine core_init() and
core_configure()") caused a network performance regression due to the GBE
LTR ignore that it added at probe. This was needed in order to allow the
SoC to enter the deepest Package C state. To fix the regression and at
least support PC10 during suspend, move the LTR ignore from probe to the
suspend callback, and enable it again on resume. This solution will allow
PC10 during suspend but restrict Package C entry at runtime to no deeper
than PC8/9 while a network cable it attach to the PCH LAN.

Fixes: 804951203aa5 ("platform/x86:intel/pmc: Combine core_init() and core_configure()")
Signed-off-by: "David E. Box" <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20231223032548.1680738-6-david.e.box@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

5 files changed, 33 insertions, 23 deletions

diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
index a887c388cf16..606f7678bcb0 100644
--- a/drivers/platform/x86/intel/pmc/adl.c
+++ b/drivers/platform/x86/intel/pmc/adl.c
@@ -314,16 +314,13 @@ int adl_core_init(struct pmc_dev *pmcdev)
 	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
 	int ret;
 
+	pmcdev->suspend = cnl_suspend;
+	pmcdev->resume = cnl_resume;
+
 	pmc->map = &adl_reg_map;
 	ret = get_primary_reg_base(pmc);
 	if (ret)
 		return ret;
 
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3, 1);
-
 	return 0;
 }
diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index 10498204962c..98b36651201a 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -204,21 +204,35 @@ const struct pmc_reg_map cnp_reg_map = {
 	.etr3_offset = ETR3_OFFSET,
 };
 
+void cnl_suspend(struct pmc_dev *pmcdev)
+{
+	/*
+	 * Due to a hardware limitation, the GBE LTR blocks PC10
+	 * when a cable is attached. To unblock PC10 during suspend,
+	 * tell the PMC to ignore it.
+	 */
+	pmc_core_send_ltr_ignore(pmcdev, 3, 1);
+}
+
+int cnl_resume(struct pmc_dev *pmcdev)
+{
+	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
+
+	return pmc_core_resume_common(pmcdev);
+}
+
 int cnp_core_init(struct pmc_dev *pmcdev)
 {
 	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
 	int ret;
 
+	pmcdev->suspend = cnl_suspend;
+	pmcdev->resume = cnl_resume;
+
 	pmc->map = &cnp_reg_map;
 	ret = get_primary_reg_base(pmc);
 	if (ret)
 		return ret;
 
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3, 1);
-
 	return 0;
 }
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index 71ba7d691d69..b66dacbfb94b 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -502,6 +502,9 @@ int tgl_core_init(struct pmc_dev *pmcdev);
 int adl_core_init(struct pmc_dev *pmcdev);
 int mtl_core_init(struct pmc_dev *pmcdev);
 
+void cnl_suspend(struct pmc_dev *pmcdev);
+int cnl_resume(struct pmc_dev *pmcdev);
+
 #define pmc_for_each_mode(i, mode, pmcdev)		\
 	for (i = 0, mode = pmcdev->lpm_en_modes[i];	\
 	     i < pmcdev->num_lpm_modes;			\
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index 71dc11811e11..504e3e273c32 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -979,6 +979,8 @@ static void mtl_d3_fixup(void)
 static int mtl_resume(struct pmc_dev *pmcdev)
 {
 	mtl_d3_fixup();
+	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
+
 	return pmc_core_resume_common(pmcdev);
 }
 
@@ -989,6 +991,7 @@ int mtl_core_init(struct pmc_dev *pmcdev)
 
 	mtl_d3_fixup();
 
+	pmcdev->suspend = cnl_suspend;
 	pmcdev->resume = mtl_resume;
 
 	pmcdev->regmap_list = mtl_pmc_info_list;
@@ -1002,11 +1005,5 @@ int mtl_core_init(struct pmc_dev *pmcdev)
 			return ret;
 	}
 
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3, 1);
-
 	return 0;
 }
diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
index 078263db24c7..e88d3d00c853 100644
--- a/drivers/platform/x86/intel/pmc/tgl.c
+++ b/drivers/platform/x86/intel/pmc/tgl.c
@@ -259,16 +259,15 @@ int tgl_core_init(struct pmc_dev *pmcdev)
 	int ret;
 
 	pmc->map = &tgl_reg_map;
+
+	pmcdev->suspend = cnl_suspend;
+	pmcdev->resume = cnl_resume;
+
 	ret = get_primary_reg_base(pmc);
 	if (ret)
 		return ret;
 
 	pmc_core_get_tgl_lpm_reqs(pmcdev->pdev);
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3, 1);
 
 	return 0;
 }