On Fri, 3 Aug 2012, Huang Ying wrote: > This patch fixes the following bug: > > http://marc.info/?l=linux-pci&m=134338059022620&w=2 > > Where lspci does not work properly if a device and the corresponding > parent bridge (such as PCIe port) is suspended. This is because the > device configuration space registers will be not accessible if the > corresponding parent bridge is suspended or the device is put into > D3cold state. > > To solve the issue, the bridge/PCIe port connected to the device is > put into active state before read/write configuration space registers. > If the device is in D3cold state, it will be put into active state > too. > > To avoid resume/suspend PCIe port for each configuration register > read/write, a small delay is added before the PCIe port to go > suspended. > +static void > +pci_config_pm_runtime_put(struct pci_dev *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device *parent = dev->parent; > + > + pm_runtime_put(dev); > + if (parent) > + pm_runtime_put(parent); > +} This is just the sort of thing Rafael and I have been talking about. Why do an asynchronous put, going to all the trouble of using the workqueue, if the idle routine is just going to call pm_schedule_suspend()? Why not call pm_runtime_put_sync() instead? Alan Stern -- 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
