From 58d9a38f6facb28e935ec2747f6d9e9bf4684118 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 21 Jan 2013 13:20:51 -0800 Subject: [PATCH] PCI: Skip attaching driver in device_add() We want to add PCI devices to the device tree as early as possible but delay attaching drivers. device_add() adds a device to the device hierarchy and (via device_attach()) attaches a matching driver and calls its .probe() method. We want to separate adding the device to the hierarchy from attaching the driver. This patch does that by adding "match_driver" in struct pci_dev. When false, we return failure from pci_bus_match(), which makes device_attach() believe there's no matching driver. Later, we set "match_driver = true" and call device_attach() again, which now attaches the driver and calls its .probe() method. [bhelgaas: changelog, explicitly init dev->match_driver, fold device_attach() call into pci_bus_add_device()] Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki --- drivers/pci/bus.c | 5 +++++ drivers/pci/pci-driver.c | 6 +++++- include/linux/pci.h | 1 + 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 847f3ca47bb8..c8709c6fdb7c 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -177,10 +177,15 @@ int pci_bus_add_device(struct pci_dev *dev) if (retval) return retval; + dev->match_driver = false; retval = device_add(&dev->dev); if (retval) return retval; + dev->match_driver = true; + retval = device_attach(&dev->dev); + WARN_ON(retval < 0); + dev->is_added = 1; pci_proc_attach_device(dev); pci_create_sysfs_dev_files(dev); diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index f79cbcd3944b..acdcc3c6ecdd 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1186,9 +1186,13 @@ pci_dev_driver(const struct pci_dev *dev) static int pci_bus_match(struct device *dev, struct device_driver *drv) { struct pci_dev *pci_dev = to_pci_dev(dev); - struct pci_driver *pci_drv = to_pci_driver(drv); + struct pci_driver *pci_drv; const struct pci_device_id *found_id; + if (!pci_dev->match_driver) + return 0; + + pci_drv = to_pci_driver(drv); found_id = pci_match_device(pci_drv, pci_dev); if (found_id) return 1; diff --git a/include/linux/pci.h b/include/linux/pci.h index 907b455ab603..8ee7e4e46539 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -286,6 +286,7 @@ struct pci_dev { unsigned int irq; struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */ + bool match_driver; /* Skip attaching driver */ /* These fields are used by common fixups */ unsigned int transparent:1; /* Transparent PCI bridge */ unsigned int multifunction:1;/* Part of multi-function device */ -- 2.20.1