On Wed, 13 Nov 2013, Bjorn Helgaas wrote: > [+cc Rafael, linux-pm] > > On Wed, Nov 13, 2013 at 6:09 AM, mike <qiudayu@xxxxxxxxxxxxxxxxxx> wrote: > > Hi Huang Ying, > > > > I see you are the author of this patch, commit id is: > > 967577b062417b4e4b8e27b711220f4124f5153a > > > > I have a question while I try to understand this patch, > > So I would very grateful if you or others can give me some reply..... > > > > ............ > > - rc = ddi->drv->probe(ddi->dev, ddi->id); > > + pm_runtime_get_sync(dev); > > + pci_dev->driver = pci_drv; > > ^^^^^^^^^^^^^^^^^^^^^^^^^^ > > I see here you make the driver to initialize before probe, > > But I have no idea of why you do this change..... > > > > and I look inside the code, it may be pm_runtime relate?? Yes, it is related to runtime PM. In the PCI subsystem, runtime PM doesn't do anything unless pci_dev->driver is set. You can see this at the start of pci_pm_runtime_suspend(). Since we want the driver's probe routine to be able to carry out runtime PM operations, we have to set pci_dev->driver before the probe routine runs. 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
