From 234f223d63d8f7db64a682ccf02871d40d38db52 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Fri, 7 Jun 2019 00:30:58 +0200
Subject: [PATCH] PCI: PM: Avoid resuming devices in D3hot during system
suspend
The current code resumes devices in D3hot during system suspend if
the target power state for them is D3cold, but that is not necessary
in general. It only is necessary to do that if the platform firmware
requires the device to be resumed, but that should be covered by
the platform_pci_need_resume() check anyway, so rework
pci_dev_keep_suspended() to avoid returning 'false' for devices
in D3hot which need not be resumed due to platform firmware
requirements.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/pci/pci.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8abc843b1615..324175509e94 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2474,10 +2474,20 @@ bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
{
struct device *dev = &pci_dev->dev;
bool wakeup = device_may_wakeup(dev);
+ pci_power_t target_state;
+
+ if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev))
+ return false;
- if (!pm_runtime_suspended(dev)
- || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
- || platform_pci_need_resume(pci_dev))
+ target_state = pci_target_state(pci_dev, wakeup);
+
+ /*
+ * If the earlier platform check has not triggered, D3cold is just power
+ * removal on top of D3hot, so no need to resume the device in that
+ * case.
+ */
+ if (target_state != pci_dev->current_state &&
+ target_state != PCI_D3cold && pci_dev->current_state != PCI_D3hot)
return false;
/*
--
2.30.9