[PATCH v1 11/11] PCI/PM: Replace pci_set_power_state() in pci_pm_thaw_noirq()

Rafael J. Wysocki
2022-05-05T18:29:04Z

Calling pci_set_power_state() to put the given device into D0 in
pci_pm_thaw_noirq() may cause it to restore the device's BARs, which
is redundant before calling pci_restore_state(), so replace it with
a direct pci_power_up() call followed by pci_update_current_state()
if it returns a nonzeor value, in analogy with
pci_pm_default_resume_early().

Avoid code duplication by introducing a wrapper function to contain
the repeating pattern and calling it in both places.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/pci/pci-driver.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

Index: linux-pm/drivers/pci/pci-driver.c
===================================================================
--- linux-pm.orig/drivers/pci/pci-driver.c
+++ linux-pm/drivers/pci/pci-driver.c
@@ -551,10 +551,15 @@ static void pci_pm_default_resume(struct
pci_enable_wake(pci_dev, PCI_D0, false);
}

-static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
+static void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
{
pci_power_up(pci_dev);
pci_update_current_state(pci_dev, PCI_D0);
+}
+
+static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
+{
+ pci_pm_power_up_and_verify_state(pci_dev);
pci_restore_state(pci_dev);
pci_pme_restore(pci_dev);
}
@@ -1079,7 +1084,7 @@ static int pci_pm_thaw_noirq(struct devi
* in case the driver's "freeze" callbacks put it into a low-power
* state.
*/
- pci_set_power_state(pci_dev, PCI_D0);
+ pci_pm_power_up_and_verify_state(pci_dev);
pci_restore_state(pci_dev);

if (pci_has_legacy_pm_support(pci_dev))