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[2/6,SRU,OEM-5.17/OEM-6.0] PCI: Pass available buses even if the bridge is already configured

Message ID 20220930082428.142684-3-chris.chiu@canonical.com
State New
Headers show
Series Fix Thunderbolt device hotplug fail when connect via thunderbolt dock | expand

Commit Message

Chris Chiu Sept. 30, 2022, 8:24 a.m. UTC 
From: Mika Westerberg <mika.westerberg@linux.intel.com>

BugLink: https://bugs.launchpad.net/bugs/1991366

If some part of the PCI topology is already configured (by the boot
firmware) but not all, and it includes hotplug bridges, we may need to
extend the bus resources of those bridges to accommodate any future
hotplugs, in the same way we already do with the normal hotplug case.

Pass the available buses to pci_scan_child_bus_extend() even when the
bridge in question is already configured so the bus allocation code can use
these available buses to extend the possible hotplug bridges below.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216000
Link: https://lore.kernel.org/r/20220905080232.36087-3-mika.westerberg@linux.intel.com
Reported-by: Chris Chiu <chris.chiu@canonical.com>
Tested-by: Chris Chiu <chris.chiu@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
(cherry picked from commit 49ad31e9d78527045614c534df057cadee487773 linux-next)
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
---
 drivers/pci/probe.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index d9b42cbaf22a..15ab8cf3d238 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1297,7 +1297,7 @@  static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 
 	if ((secondary || subordinate) && !pcibios_assign_all_busses() &&
 	    !is_cardbus && !broken) {
-		unsigned int cmax;
+		unsigned int cmax, buses;
 
 		/*
 		 * Bus already configured by firmware, process it in the
@@ -1322,7 +1322,8 @@  static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 			child->bridge_ctl = bctl;
 		}
 
-		cmax = pci_scan_child_bus(child);
+		buses = subordinate - secondary;
+		cmax = pci_scan_child_bus_extend(child, buses);
 		if (cmax > subordinate)
 			pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n",
 				 subordinate, cmax);