[v2,9/9] PCI/PM: Replace pci_set_power_state() in pci_pm_thaw_noirq()

Commit Message

Rafael J. Wysocki April 11, 2022, 2:33 p.m. UTC

From: Rafael J. Wysocki <[e-mail]>

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 <[e-mail]>
---

New patch in v2.

---
 drivers/pci/pci-driver.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Patch

Index: linux-pm/drivers/pci/pci-driver.c
===================================================================
--- linux-pm.orig/drivers/pci/pci-driver.c
+++ linux-pm/drivers/pci/pci-driver.c
@@ -551,11 +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)
 {
 	if (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);
 }
@@ -1080,7 +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))