Hi Thomas, On Thu, Jan 22, 2015 at 05:40:00PM +0000, Thomas Petazzoni wrote: > Dear Yijing Wang, > > On Wed, 21 Jan 2015 08:30:18 +0800, Yijing Wang wrote: > > Mvebu_pcie_scan_bus() is not necessary, we could use > > pci_common_init_dev() instead of pci_common_init(), > > and pass the device pointer as the parent. Then > > pci_scan_root_bus() will be called to scan the pci busses. > > > > Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx> > > CC: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> > > CC: Jason Cooper <jason@xxxxxxxxxxxxxx> > > While I'm fine with the change to pci_common_init_dev(), I am not so > sure about the removal of mvebu_pcie_scan_bus(). I vaguely remember > that we intentionally did not use the default function for a specific > reason. Of course, this was a long time ago, and I don't remember the > reason. I would have to take a bit of time to 1/ review the archives of > the discussion surrounding the pcie-mvebu driver, and 2/ test your > patch to validate it works fine on HW. I guess the reason: by providing the scan pointer to pcibios through the hw_pci struct you were preventing calling pci_scan_root_bus() in bios32.c that in turn can add devices before the resources are assigned. Basically mvebu_pci_scan_bus() was doing what pci_scan_root_bus() does except for calling pci_bus_add_devices(). Yijing patches remove pci_bus_add_devices() from pci_scan_root_bus() so his change should be fine and it actually improves the current behaviour which is quite hard to untangle, and not just on mvebu (I suspect drivers/pci/host/pcie-xilinx.c can suffer from the same problem). Lorenzo > > Thanks! > > Thomas > -- > Thomas Petazzoni, CTO, Free Electrons > Embedded Linux, Kernel and Android engineering > http://free-electrons.com > -- > 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 > -- 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
