From a5f40e8098fe6d983fdb3beb7b50a8067c136141 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Thu, 20 Apr 2017 15:36:25 -0500 Subject: PCI: Don't allow unbinding host controllers that aren't prepared Many PCI host controller drivers aren't prepared to have their devices unbound from them forcefully (e.g., through /sys/...//unbind), as they don't provide any driver .remove callback, where they'd detach the root bus, release resources, etc. Keeping the driver built in (i.e., not a loadable module) is not enough; and providing no .remove callback just means we don't do any teardown. To rule out the possibility of unbinding a device via sysfs, we need to set the ".suppress_bind_attrs" field. I found the suspect drivers via the following search: git grep -l platform_driver $(git grep -L -e '\.remove' -e suppress_bind_attrs drivers/pci/) Then I inspected them to ensure that (a) they set up a PCI bus in their probe() and (b) they don't have a remove() callback for undoing the setup Suggested-by: Bjorn Helgaas Signed-off-by: Brian Norris Signed-off-by: Bjorn Helgaas --- drivers/pci/host/pci-host-generic.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/pci/host/pci-host-generic.c') diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c index c05ea9d72f69..7d709a7e0aa8 100644 --- a/drivers/pci/host/pci-host-generic.c +++ b/drivers/pci/host/pci-host-generic.c @@ -60,6 +60,7 @@ static struct platform_driver gen_pci_driver = { .driver = { .name = "pci-host-generic", .of_match_table = gen_pci_of_match, + .suppress_bind_attrs = true, }, .probe = gen_pci_probe, }; -- cgit v1.2.3