From 40b3880dc29b89c39139eba11eba2b3107dc2e38 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 31 Jan 2023 09:24:59 +0100 Subject: driver core: platform: simplify __platform_driver_probe() __platform_driver_probe() pokes around in some bus and driver private lists and locks in a way that is not needed at all. The code only wants to know if a device was bound to the driver that was registered, so walk all devices on the bus to see if there was a match. If there is not a match, return an error. This is the same logic as was originally present, but just done in a simpler and more obvious way that is not a layering violation. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230131082459.301603-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 423874269f9d..77510e4f47de 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -883,6 +883,13 @@ static int platform_probe_fail(struct platform_device *pdev) return -ENXIO; } +static int is_bound_to_driver(struct device *dev, void *driver) +{ + if (dev->driver == driver) + return 1; + return 0; +} + /** * __platform_driver_probe - register driver for non-hotpluggable device * @drv: platform driver structure @@ -936,20 +943,17 @@ int __init_or_module __platform_driver_probe(struct platform_driver *drv, if (retval) return retval; - /* - * Fixup that section violation, being paranoid about code scanning - * the list of drivers in order to probe new devices. Check to see - * if the probe was successful, and make sure any forced probes of - * new devices fail. - */ - spin_lock(&drv->driver.bus->p->klist_drivers.k_lock); + /* Force all new probes of this driver to fail */ drv->probe = platform_probe_fail; - if (list_empty(&drv->driver.p->klist_devices.k_list)) - retval = -ENODEV; - spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock); - if (retval) + /* Walk all platform devices and see if any actually bound to this driver. + * If not, return an error as the device should have done so by now. + */ + if (!bus_for_each_dev(&platform_bus_type, NULL, &drv->driver, is_bound_to_driver)) { + retval = -ENODEV; platform_driver_unregister(drv); + } + return retval; } EXPORT_SYMBOL_GPL(__platform_driver_probe); -- cgit