PCI: Add debug print when releasing resources before retry

PCI resource fitting is somewhat hard to track because it performs many
actions without logging them. In the case inside
__assign_resources_sorted(), the resources are released before resource
assignment is going to be retried in a different order. That is just one
level of retries the resource fitting performs overall so tracking it
through repeated assignments or failures of a resource gets messy rather
quickly.

Simply announce the release explicitly using pci_dbg() so it is clear what
is going on with each resource.

Link: https://lore.kernel.org/r/20241216175632.4175-23-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xiaochun Lee <lixc17@lenovo.com>

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index c80162d6aefd052146273e7ad2583344f1ecd385..5bebfeb6c417ab20525c334b0678964ff8acea4c 100644 (file)
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -408,6 +408,9 @@ static void __assign_resources_sorted(struct list_head *head,
        struct pci_dev_resource *save_res;
        struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
        struct resource *res;
+       struct pci_dev *dev;
+       const char *res_name;
+       int idx;
        unsigned long fail_type;
        resource_size_t add_align, align;
 
@@ -497,9 +500,16 @@ static void __assign_resources_sorted(struct list_head *head,
        /* Release assigned resource */
        list_for_each_entry(dev_res, head, list) {
                res = dev_res->res;
+               dev = dev_res->dev;
+
+               if (!res->parent)
+                       continue;
+
+               idx = pci_resource_num(dev, res);
+               res_name = pci_resource_name(dev, idx);
+               pci_dbg(dev, "%s %pR: releasing\n", res_name, res);
 
-               if (res->parent)
-                       release_resource(res);
+               release_resource(res);
        }
        /* Restore start/end/flags from saved list */
        list_for_each_entry(save_res, &save_head, list)