diff mbox series

[1/3,SRU,Oracular] platform/x86: intel/pmc: Ignore all LTRs during suspend

Message ID 20241021042358.2200586-2-vicamo.yang@canonical.com
State New
Headers show
Series Intel(R) PRO/1000 I219 ethernet adapter [8086:550c] may block entrance of modern standby | expand

Commit Message

You-Sheng Yang Oct. 21, 2024, 4:23 a.m. UTC
From: Xi Pardee <xi.pardee@intel.com>

BugLink: https://bugs.launchpad.net/bugs/2081130

Add support to ignore all LTRs before suspend and restore the previous
LTR values after suspend. This feature could be turned off with module
parameter ltr_ignore_all_suspend.

LTR value is a mechanism for a device to indicate tolerance to access
the corresponding resource. When system suspends, the resource is not
available and therefore the LTR value could be ignored. Ignoring all
LTR values prevents problematic device from blocking the system to get
to the deepest package state during suspend.

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Xi Pardee <xi.pardee@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240906184016.268153-1-xi.pardee@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
(cherry picked from commit cedf233530cc375343c5a0b612fe94392f246c99)
Signed-off-by: You-Sheng Yang <vicamo.yang@canonical.com>
---
 drivers/platform/x86/intel/pmc/core.c | 53 +++++++++++++++++++++++++++
 drivers/platform/x86/intel/pmc/core.h |  2 +
 2 files changed, 55 insertions(+)
diff mbox series

Patch

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 01ae71c6df59d..0ec703af16a4b 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -714,6 +714,49 @@  static int pmc_core_s0ix_blocker_show(struct seq_file *s, void *unused)
 }
 DEFINE_SHOW_ATTRIBUTE(pmc_core_s0ix_blocker);
 
+static void pmc_core_ltr_ignore_all(struct pmc_dev *pmcdev)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(pmcdev->pmcs); i++) {
+		struct pmc *pmc;
+		u32 ltr_ign;
+
+		pmc = pmcdev->pmcs[i];
+		if (!pmc)
+			continue;
+
+		guard(mutex)(&pmcdev->lock);
+		pmc->ltr_ign = pmc_core_reg_read(pmc, pmc->map->ltr_ignore_offset);
+
+		/* ltr_ignore_max is the max index value for LTR ignore register */
+		ltr_ign = pmc->ltr_ign | GENMASK(pmc->map->ltr_ignore_max, 0);
+		pmc_core_reg_write(pmc, pmc->map->ltr_ignore_offset, ltr_ign);
+	}
+
+	/*
+	 * Ignoring ME during suspend is blocking platforms with ADL PCH to get to
+	 * deeper S0ix substate.
+	 */
+	pmc_core_send_ltr_ignore(pmcdev, 6, 0);
+}
+
+static void pmc_core_ltr_restore_all(struct pmc_dev *pmcdev)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(pmcdev->pmcs); i++) {
+		struct pmc *pmc;
+
+		pmc = pmcdev->pmcs[i];
+		if (!pmc)
+			continue;
+
+		guard(mutex)(&pmcdev->lock);
+		pmc_core_reg_write(pmc, pmc->map->ltr_ignore_offset, pmc->ltr_ign);
+	}
+}
+
 static inline u64 adjust_lpm_residency(struct pmc *pmc, u32 offset,
 				       const int lpm_adj_x2)
 {
@@ -1479,6 +1522,10 @@  static bool warn_on_s0ix_failures;
 module_param(warn_on_s0ix_failures, bool, 0644);
 MODULE_PARM_DESC(warn_on_s0ix_failures, "Check and warn for S0ix failures");
 
+static bool ltr_ignore_all_suspend = true;
+module_param(ltr_ignore_all_suspend, bool, 0644);
+MODULE_PARM_DESC(ltr_ignore_all_suspend, "Ignore all LTRs during suspend");
+
 static __maybe_unused int pmc_core_suspend(struct device *dev)
 {
 	struct pmc_dev *pmcdev = dev_get_drvdata(dev);
@@ -1488,6 +1535,9 @@  static __maybe_unused int pmc_core_suspend(struct device *dev)
 	if (pmcdev->suspend)
 		pmcdev->suspend(pmcdev);
 
+	if (ltr_ignore_all_suspend)
+		pmc_core_ltr_ignore_all(pmcdev);
+
 	/* Check if the syspend will actually use S0ix */
 	if (pm_suspend_via_firmware())
 		return 0;
@@ -1594,6 +1644,9 @@  static __maybe_unused int pmc_core_resume(struct device *dev)
 {
 	struct pmc_dev *pmcdev = dev_get_drvdata(dev);
 
+	if (ltr_ignore_all_suspend)
+		pmc_core_ltr_restore_all(pmcdev);
+
 	if (pmcdev->resume)
 		return pmcdev->resume(pmcdev);
 
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index ea04de7eb9e84..e862ea88b816e 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -372,6 +372,7 @@  struct pmc_info {
  * @map:		pointer to pmc_reg_map struct that contains platform
  *			specific attributes
  * @lpm_req_regs:	List of substate requirements
+ * @ltr_ign:		Holds LTR ignore data while suspended
  *
  * pmc contains info about one power management controller device.
  */
@@ -380,6 +381,7 @@  struct pmc {
 	void __iomem *regbase;
 	const struct pmc_reg_map *map;
 	u32 *lpm_req_regs;
+	u32 ltr_ign;
 };
 
 /**