On Fri, Apr 12, 2013 at 11:50 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > On Fri, Apr 12, 2013 at 4:58 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: >> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> >> >> Commit b51306c (PCI: Set device power state to PCI_D0 for device >> without native PM support) modified pci_platform_power_transition() >> by adding code causing dev->current_state for devices that don't >> support native PCI PM but are power-manageable by the platform to be >> changed to PCI_D0 regardless of the value returned by the preceding >> platform_pci_set_power_state(). In particular, that also is done >> if the platform_pci_set_power_state() has been successful, which >> causes the correct power state of the device set by >> pci_update_current_state() in that case to be overwritten by PCI_D0. >> >> Fix that mistake by making the fallback to PCI_D0 only happen if >> the platform_pci_set_power_state() has returned an error. >> >> Reported-by: Chris J. Benenati <chris.j.benenati@xxxxxxxxx> >> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> >> Cc: <stable@xxxxxxxxxxxxxxx> I folded in Yinghai's simplification and added a URL to Chris's report and applied to my pci/rafael-pm branch: http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/rafael-pm If it still looks good to you, Rafael, I'll merge it to next for v3.10. I don't know what the user-visible effect of this is, and it's been around for a long time, but if you think this should go in v3.9 instead, let me know. Bjorn >> --- >> drivers/pci/pci.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> Index: linux-pm/drivers/pci/pci.c >> =================================================================== >> --- linux-pm.orig/drivers/pci/pci.c >> +++ linux-pm/drivers/pci/pci.c >> @@ -646,8 +646,7 @@ static int pci_platform_power_transition >> error = platform_pci_set_power_state(dev, state); >> if (!error) >> pci_update_current_state(dev, state); >> - /* Fall back to PCI_D0 if native PM is not supported */ >> - if (!dev->pm_cap) >> + else if (!dev->pm_cap) /* Fall back to PCI_D0 */ >> dev->current_state = PCI_D0; >> } else { >> error = -ENODEV; >> > > Acked-by: Yinghai Lu <yinghai@xxxxxxxxxx> > > also could simplify it further. > > --- > drivers/pci/pci.c | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) > > Index: linux-2.6/drivers/pci/pci.c > =================================================================== > --- linux-2.6.orig/drivers/pci/pci.c > +++ linux-2.6/drivers/pci/pci.c > @@ -646,15 +646,11 @@ static int pci_platform_power_transition > error = platform_pci_set_power_state(dev, state); > if (!error) > pci_update_current_state(dev, state); > - /* Fall back to PCI_D0 if native PM is not supported */ > - if (!dev->pm_cap) > - dev->current_state = PCI_D0; > - } else { > + } else > error = -ENODEV; > - /* Fall back to PCI_D0 if native PM is not supported */ > - if (!dev->pm_cap) > - dev->current_state = PCI_D0; > - } > + > + if (error && !dev->pm_cap) /* Fall back to PCI_D0 */ > + dev->current_state = PCI_D0; > > return error; > } -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
