From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [PATCH 24/30] ACPI / hotplug / PCI: Allow slots without new devices to be rescanned Date: Thu, 18 Jul 2013 01:31:52 +0200 Message-ID: <1681066.kN23ZaLIQQ@vostro.rjw.lan> References: <26431283.HJCKsss0rt@vostro.rjw.lan> <3718119.FLASu5DBx8@vostro.rjw.lan> <2366394.4EoP1MXmG2@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <2366394.4EoP1MXmG2@vostro.rjw.lan> Sender: linux-pci-owner@vger.kernel.org To: ACPI Devel Maling List Cc: Bjorn Helgaas , LKML , Linux PCI , Yinghai Lu , Jiang Liu , Mika Westerberg , "Kirill A. Shutemov" List-Id: linux-acpi@vger.kernel.org From: Kirill A. Shutemov Currently, enable_device() checks the return value of pci_scan_slot() and returns immediately if that's 0 (meaning that no new functions have been found in the slot). However, if one of the functions in the slot is a bridge, some new devices may appear below it even if the bridge itself is present continuously, so it generally is necessary to do the rescan anyway just in case. [In particular, that's necessary with the Thunderbolt daisy chaining in which case new devices may be connected to the existing ones down the chain.] The correctness of this change relies on the ability of pcibios_resource_survey_bus() to detect if it has already been called for the given bus and to skip it if so. Failure to do that will lead to resource allocation conflicts. [rjw: Changelog] Signed-off-by: Kirill A. Shutemov Signed-off-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki --- drivers/pci/hotplug/acpiphp_glue.c | 11 ++--------- drivers/pci/hotplug/acpiphp_glue.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c =================================================================== --- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c +++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c @@ -542,18 +542,13 @@ static int __ref enable_device(struct ac struct pci_dev *dev; struct pci_bus *bus = slot->bus; struct acpiphp_func *func; - int num, max, pass; + int max, pass; LIST_HEAD(add_list); list_for_each_entry(func, &slot->funcs, sibling) acpiphp_bus_add(func_to_handle(func)); - num = pci_scan_slot(bus, PCI_DEVFN(slot->device, 0)); - if (num == 0) { - /* Maybe only part of funcs are added. */ - dbg("No new device found\n"); - goto err_exit; - } + pci_scan_slot(bus, PCI_DEVFN(slot->device, 0)); max = acpiphp_max_busnr(bus); for (pass = 0; pass < 2; pass++) { @@ -599,8 +594,6 @@ static int __ref enable_device(struct ac } } - - err_exit: return 0; }