From a3b93b42238b3bb9eefc25729f567e66eea66a56 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Thu, 19 Feb 2026 00:34:18 +0200 Subject: [PATCH] PCI: Account fully optional bridge windows correctly MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit pbus_size_mem_optional() adds dev_res->add_size of a bridge window into children_add_size when the window has a non-optional part. However, if the bridge window is fully optional, only r_size is added (which is zero for such a window). Also, a second dev_res entry will be added by pci_dev_res_add_to_list() into realloc_head for the bridge window (resulting in triggering the realloc_head-must-be-fully-consumed sanity check after a single pass of the resource assignment algorithm): WARNING: drivers/pci/setup-bus.c:2153 at pci_assign_unassigned_root_bus_resources+0xa5/0x260 Correct these problems by always adding dev_res->add_size for bridge windows and not calling pci_dev_res_add_to_list() if the dev_res entry exists. Fixes: 6a5e64c75e82 ("PCI: Add pbus_mem_size_optional() to handle optional sizes") Reported-by: RavitejaX Veesam Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Tested-by: RavitejaX Veesam Link: https://patch.msgid.link/20260218223419.22366-1-ilpo.jarvinen@linux.intel.com --- drivers/pci/setup-bus.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index f30d1f7f023a..bd66ac47b3b9 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1224,31 +1224,34 @@ static bool pbus_size_mem_optional(struct pci_dev *dev, int resno, struct resource *res = pci_resource_n(dev, resno); bool optional = pci_resource_is_optional(dev, resno); resource_size_t r_size = resource_size(res); - struct pci_dev_resource *dev_res; + struct pci_dev_resource *dev_res = NULL; if (!realloc_head) return false; - if (!optional) { - /* - * Only bridges have optional sizes in realloc_head at this - * point. As res_to_dev_res() walks the entire realloc_head - * list, skip calling it when known unnecessary. - */ - if (!pci_resource_is_bridge_win(resno)) - return false; - + /* + * Only bridges have optional sizes in realloc_head at this + * point. As res_to_dev_res() walks the entire realloc_head + * list, skip calling it when known unnecessary. + */ + if (pci_resource_is_bridge_win(resno)) { dev_res = res_to_dev_res(realloc_head, res); if (dev_res) { *children_add_size += dev_res->add_size; *add_align = max(*add_align, dev_res->min_align); } + } + if (!optional) return false; - } - /* Put SRIOV requested res to the optional list */ - pci_dev_res_add_to_list(realloc_head, dev, res, 0, align); + /* + * Put requested res to the optional list if not there yet (SR-IOV, + * disabled ROM). Bridge windows with an optional part are already + * on the list. + */ + if (!dev_res) + pci_dev_res_add_to_list(realloc_head, dev, res, 0, align); *children_add_size += r_size; *add_align = max(align, *add_align); -- 2.47.3