PCI/PM: Add needs_resume flag to avoid suspend complete optimization

Some drivers - like i915 - may not support the system suspend direct
complete optimization due to differences in their runtime and system
suspend sequence.  Add a flag that when set resumes the device before
calling the driver's system suspend handlers which effectively disables
the optimization.

Needed by a future patch fixing suspend/resume on i915.

Suggested by Rafael.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b01bd5bba8e604709c3b51f14f9fbdb796a2c4fb..563901cd9c06b839f4eea9a74ed78f76309f7f62 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2144,7 +2144,8 @@ bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
 
        if (!pm_runtime_suspended(dev)
            || pci_target_state(pci_dev) != pci_dev->current_state
-           || platform_pci_need_resume(pci_dev))
+           || platform_pci_need_resume(pci_dev)
+           || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME))
                return false;
 
        /*

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 33c2b0b77429d09aaa31cb9735458db5762e08a7..df7dd9021646b5fbea65695545219bd091ae4717 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -183,6 +183,11 @@ enum pci_dev_flags {
        PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT = (__force pci_dev_flags_t) (1 << 9),
        /* Do not use FLR even if device advertises PCI_AF_CAP */
        PCI_DEV_FLAGS_NO_FLR_RESET = (__force pci_dev_flags_t) (1 << 10),
+       /*
+        * Resume before calling the driver's system suspend hooks, disabling
+        * the direct_complete optimization.
+        */
+       PCI_DEV_FLAGS_NEEDS_RESUME = (__force pci_dev_flags_t) (1 << 11),
 };
 
 enum pci_irq_reroute_variant {