| Message ID | 20171110175230.82522-2-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2,1/2] powerpc/pci: convert to use for_each_pci_bridge() helper | expand |
On Fri, Nov 10, 2017 at 07:52:30PM +0200, Andy Shevchenko wrote: > The current scanning code is really hard to understand because it calls > the same function in a loop where pass value is changed without any > comments explaining it: > > for (pass = 0; pass < 2; pass++) > for_each_pci_bridge(dev, bus) > max = pci_scan_bridge(bus, dev, max, pass); > > Unfamiliar reader cannot tell easily what is the purpose of this loop > without looking at internals of pci_scan_bridge(). > > In order to make this bit easier to understand, open-code the loop in > pci_scan_child_bus() and pci_hp_add_bridge() with added comments. > > No functional changes intended. > > Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c index 741f47295188..cf47b1aec4c2 100644 --- a/arch/powerpc/kernel/pci-hotplug.c +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -104,7 +104,7 @@ EXPORT_SYMBOL_GPL(pci_hp_remove_devices); */ void pci_hp_add_devices(struct pci_bus *bus) { - int slotno, mode, pass, max; + int slotno, mode, max; struct pci_dev *dev; struct pci_controller *phb; struct device_node *dn = pci_bus_to_OF_node(bus); @@ -133,10 +133,17 @@ void pci_hp_add_devices(struct pci_bus *bus) pci_scan_slot(bus, PCI_DEVFN(slotno, 0)); pcibios_setup_bus_devices(bus); max = bus->busn_res.start; - for (pass = 0; pass < 2; pass++) { - for_each_pci_bridge(dev, bus) - max = pci_scan_bridge(bus, dev, max, pass); - } + /* + * Scan bridges that are already configured. We don't touch + * them unless they are misconfigured (which will be done in + * the second scan below). + */ + for_each_pci_bridge(dev, bus) + max = pci_scan_bridge(bus, dev, max, 0); + + /* Scan bridges that need to be reconfigured */ + for_each_pci_bridge(dev, bus) + max = pci_scan_bridge(bus, dev, max, 1); } pcibios_finish_adding_to_bus(bus); }
The current scanning code is really hard to understand because it calls the same function in a loop where pass value is changed without any comments explaining it: for (pass = 0; pass < 2; pass++) for_each_pci_bridge(dev, bus) max = pci_scan_bridge(bus, dev, max, pass); Unfamiliar reader cannot tell easily what is the purpose of this loop without looking at internals of pci_scan_bridge(). In order to make this bit easier to understand, open-code the loop in pci_scan_child_bus() and pci_hp_add_bridge() with added comments. No functional changes intended. Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- arch/powerpc/kernel/pci-hotplug.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)