We should not release bridge resource if there is fixed resources under it, otherwise the children firmware would stop working.
Reported-by: Paul Johnson <p...@nwtrail.com> Suggested-by: Bjorn Helgaas <bhelg...@google.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=92351 Signed-off-by: Yinghai Lu <ying...@kernel.org> Cc: sta...@vger.kernel.org --- drivers/pci/setup-bus.c | 6 ++++-- include/linux/ioport.h | 2 +- kernel/resource.c | 28 ++++++++++++++++++++++++++-- 3 files changed, 31 insertions(+), 5 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 0845a57..815d2de 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1540,14 +1540,16 @@ static void pci_bridge_release_resources(struct pci_bus *bus, r = &b_res[idx]; - if (!r->parent) + if (!r->parent || r->flags & IORESOURCE_PCI_FIXED) return; /* * if there are children under that, we should release them * all */ - release_child_resources(r); + if (!release_child_resources(r)) + return; + if (!release_resource(r)) { type = old_flags = r->flags & type_mask; dev_printk(KERN_DEBUG, &dev->dev, "resource %d %pR released\n", diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 0b65543..9053ac9 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -165,7 +165,7 @@ extern struct resource iomem_resource; extern struct resource *request_resource_conflict(struct resource *root, struct resource *new); extern int request_resource(struct resource *root, struct resource *new); extern int release_resource(struct resource *new); -void release_child_resources(struct resource *new); +bool release_child_resources(struct resource *new); extern void reserve_region_with_split(struct resource *root, resource_size_t start, resource_size_t end, const char *name); diff --git a/kernel/resource.c b/kernel/resource.c index 2e78ead..c5dbe02 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -285,11 +285,35 @@ static void __release_child_resources(struct resource *r) } } -void release_child_resources(struct resource *r) +static bool __has_fixed_child_resources(struct resource *r) { + struct resource *p; + + p = r->child; + while (p) { + if (p->flags & IORESOURCE_PCI_FIXED) + return true; + + if (__has_fixed_child_resources(p)) + return true; + + p = p->sibling; + } + + return false; +} + +bool release_child_resources(struct resource *r) +{ + bool fixed; + write_lock(&resource_lock); - __release_child_resources(r); + fixed = __has_fixed_child_resources(r); + if (!fixed) + __release_child_resources(r); write_unlock(&resource_lock); + + return !fixed; } /** -- 1.8.4.5
