diff mbox series

[v2,3/9] PCI/PM: Rearrange pci_update_current_state()

Message ID 4721615.GXAFRqVoOG@kreacher (mailing list archive)
State Superseded
Headers show
Series PCI/PM: Improvements related to device transitions into D0 | expand

Commit Message

Rafael J. Wysocki April 11, 2022, 2:21 p.m. UTC 
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Save one config space access in pci_update_current_state() by
testing the retireved PCI_PM_CTRL register value against
PCI_POSSIBLE_ERROR() instead of invoking pci_device_is_present()
separately.

While at it, drop a pair of unnecessary parens.

No expected functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

v1 -> v2: No changes.

---
 drivers/pci/pci.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Comments

Mika Westerberg April 12, 2022, 9:42 a.m. UTC | #1 
On Mon, Apr 11, 2022 at 04:21:04PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Save one config space access in pci_update_current_state() by
> testing the retireved PCI_PM_CTRL register value against
              ^^^^^^^^^
retrieved
Rafael J. Wysocki April 12, 2022, 10:56 a.m. UTC | #2 
On Tue, Apr 12, 2022 at 12:54 PM Mika Westerberg
<mika.westerberg@linux.intel.com> wrote:
>
> On Mon, Apr 11, 2022 at 04:21:04PM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Save one config space access in pci_update_current_state() by
> > testing the retireved PCI_PM_CTRL register value against
>               ^^^^^^^^^
> retrieved

Yup, thanks!
diff mbox series

Patch

Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -1201,14 +1201,17 @@  static int pci_raw_set_power_state(struc
  */
 void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
 {
-	if (platform_pci_get_power_state(dev) == PCI_D3cold ||
-	    !pci_device_is_present(dev)) {
+	if (platform_pci_get_power_state(dev) == PCI_D3cold) {
 		dev->current_state = PCI_D3cold;
 	} else if (dev->pm_cap) {
 		u16 pmcsr;
 
 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
-		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
+		if (PCI_POSSIBLE_ERROR(pmcsr)) {
+			dev->current_state = PCI_D3cold;
+			return;
+		}
+		dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
 	} else {
 		dev->current_state = state;
 	}