| Message ID | 20240227062648.16579-1-raag.jadav@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] PCI / PM: Really allow runtime PM without callback functions | expand |
On Tue, Feb 27, 2024 at 11:56:48AM +0530, Raag Jadav wrote: > Commit c5eb1190074c ("PCI / PM: Allow runtime PM without callback > functions") tried to eliminate the need for runtime PM callbacks by > modifying pci_pm_runtime_suspend() and pci_pm_runtime_resume(), but > didn't modify pci_pm_runtime_idle() with relevant changes, which still > returns -ENOSYS if the driver supplies no runtime PM callbacks. > > Modify pci_pm_runtime_idle() such that it allows PCI device power state > transitions without runtime PM callbacks and complete the original > intention of commit c5eb1190074c ("PCI / PM: Allow runtime PM without > callback functions"). > > Signed-off-by: Raag Jadav <raag.jadav@intel.com> > Acked-by: Rafael J. Wysocki <rafael@kernel.org> > Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> Applied to pci/pm for v6.9, thanks! I updated the commit log to try to clarify which drivers would be affected. Now that I worked through those details, I see that it was all there from the beginning and it just took a long time to sink into my head: PCI/PM: Allow runtime PM with no PM callbacks at all Commit c5eb1190074c ("PCI / PM: Allow runtime PM without callback functions") eliminated the need for PM callbacks in pci_pm_runtime_suspend() and pci_pm_runtime_resume(), but didn't do the same for pci_pm_runtime_idle(). Therefore, runtime suspend worked as long as the driver implemented at least one PM callback. But if the driver doesn't implement any PM callbacks at all (driver->pm is NULL), pci_pm_runtime_idle() returned -ENOSYS, which prevented runtime suspend. Modify pci_pm_runtime_idle() to allow PCI device power state transitions without runtime PM callbacks and complete the original intention of commit c5eb1190074c ("PCI / PM: Allow runtime PM without callback functions"). Bjorn > --- > > This is not marked for linux-stable for the need of extensive testing > and can be backported after a few releases if no issues are reported. > > Changes since v1: > - Update commit message and tags > > drivers/pci/pci-driver.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index 51ec9e7e784f..bb7f6775b350 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -1382,10 +1382,7 @@ static int pci_pm_runtime_idle(struct device *dev) > if (!pci_dev->driver) > return 0; > > - if (!pm) > - return -ENOSYS; > - > - if (pm->runtime_idle) > + if (pm && pm->runtime_idle) > return pm->runtime_idle(dev); > > return 0; > -- > 2.35.3 >
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 51ec9e7e784f..bb7f6775b350 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1382,10 +1382,7 @@ static int pci_pm_runtime_idle(struct device *dev) if (!pci_dev->driver) return 0; - if (!pm) - return -ENOSYS; - - if (pm->runtime_idle) + if (pm && pm->runtime_idle) return pm->runtime_idle(dev); return 0;
Commit c5eb1190074c ("PCI / PM: Allow runtime PM without callback functions") tried to eliminate the need for runtime PM callbacks by modifying pci_pm_runtime_suspend() and pci_pm_runtime_resume(), but didn't modify pci_pm_runtime_idle() with relevant changes, which still returns -ENOSYS if the driver supplies no runtime PM callbacks. Modify pci_pm_runtime_idle() such that it allows PCI device power state transitions without runtime PM callbacks and complete the original intention of commit c5eb1190074c ("PCI / PM: Allow runtime PM without callback functions"). Signed-off-by: Raag Jadav <raag.jadav@intel.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> --- This is not marked for linux-stable for the need of extensive testing and can be backported after a few releases if no issues are reported. Changes since v1: - Update commit message and tags drivers/pci/pci-driver.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)