kernel/linux.git/drivers/base/driver.c, branch v6.6.132

driver core: create bus_is_registered()

2023-02-09T09:43:35+00:00

A local function to the driver core to determine if a bus really is registered with the kernel or not. To be used only by the driver core code, as part of the driver registration path as it's not really "safe" because the bus could be unregistered instantly after being called. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230208111330.439504-17-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: move driver_find() to bus.c

2023-02-09T09:43:31+00:00

This function really is a bus function, not a driver one, so move it from driver.c to bus.c so that we can clean up some internal bus logic easier. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230208111330.439504-15-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: fix driver_set_override() issue with empty strings

2022-09-05T11:01:34+00:00

Python likes to send an empty string for some sysfs files, including the driver_override field. When commit 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding") moved the PCI core to use the driver core function instead of hand-rolling their own handler, this showed up as a regression from some userspace tools, like DPDK. Fix this up by actually looking at the length of the string first instead of trusting that userspace got it correct. Fixes: 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding") Cc: Krzysztof Kozlowski Cc: Bjorn Helgaas Cc: "Rafael J. Wysocki" Cc: Andy Shevchenko Cc: stable Reported-by: Stephen Hemminger Tested-by: Huisong Li Reviewed-by: Stephen Hemminger Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20220901163734.3583106-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: Extend deferred probe timeout on driver registration

2022-05-19T17:32:33+00:00

The deferred probe timer that's used for this currently starts at late_initcall and runs for driver_deferred_probe_timeout seconds. The assumption being that all available drivers would be loaded and registered before the timer expires. This means, the driver_deferred_probe_timeout has to be pretty large for it to cover the worst case. But if we set the default value for it to cover the worst case, it would significantly slow down the average case. For this reason, the default value is set to 0. Also, with CONFIG_MODULES=y and the current default values of driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing drivers will cause their consumer devices to always defer their probes. This is because device links created by fw_devlink defer the probe even before the consumer driver's probe() is called. Instead of a fixed timeout, if we extend an unexpired deferred probe timer on every successful driver registration, with the expectation more modules would be loaded in the near future, then the default value of driver_deferred_probe_timeout only needs to be as long as the worst case time difference between two consecutive module loads. So let's implement that and set the default value to 10 seconds when CONFIG_MODULES=y. Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Rob Herring Cc: Linus Walleij Cc: Will Deacon Cc: Ulf Hansson Cc: Kevin Hilman Cc: Thierry Reding Cc: Mark Brown Cc: Pavel Machek Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: Paul Kocialkowski Cc: linux-gpio@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: iommu@lists.linux-foundation.org Reviewed-by: Mark Brown Acked-by: Rob Herring Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20220429220933.1350374-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver: platform: Add helper for safer setting of driver_override

2022-04-22T15:13:53+00:00

Several core drivers and buses expect that driver_override is a dynamically allocated memory thus later they can kfree() it. However such assumption is not documented, there were in the past and there are already users setting it to a string literal. This leads to kfree() of static memory during device release (e.g. in error paths or during unbind): kernel BUG at ../mm/slub.c:3960! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM ... (kfree) from [] (platform_device_release+0x88/0xb4) (platform_device_release) from [] (device_release+0x2c/0x90) (device_release) from [] (kobject_put+0xec/0x20c) (kobject_put) from [] (exynos5_clk_probe+0x154/0x18c) (exynos5_clk_probe) from [] (platform_drv_probe+0x6c/0xa4) (platform_drv_probe) from [] (really_probe+0x280/0x414) (really_probe) from [] (driver_probe_device+0x78/0x1c4) (driver_probe_device) from [] (bus_for_each_drv+0x74/0xb8) (bus_for_each_drv) from [] (__device_attach+0xd4/0x16c) (__device_attach) from [] (bus_probe_device+0x88/0x90) (bus_probe_device) from [] (device_add+0x3dc/0x62c) (device_add) from [] (of_platform_device_create_pdata+0x94/0xbc) (of_platform_device_create_pdata) from [] (of_platform_bus_create+0x1a8/0x4fc) (of_platform_bus_create) from [] (of_platform_bus_create+0x20c/0x4fc) (of_platform_bus_create) from [] (of_platform_populate+0x84/0x118) (of_platform_populate) from [] (of_platform_default_populate_init+0xa0/0xb8) (of_platform_default_populate_init) from [] (do_one_initcall+0x8c/0x404) Provide a helper which clearly documents the usage of driver_override. This will allow later to reuse the helper and reduce the amount of duplicated code. Convert the platform driver to use a new helper and make the driver_override field const char (it is not modified by the core). Reviewed-by: Rafael J. Wysocki Acked-by: Rafael J. Wysocki Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20220419113435.246203-2-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman

drivers: base: Convert to printk alias functions

2020-07-10T12:16:44+00:00

The file mixes printk calls together with calls to pr_*(). Covert to printk alias functions to unify the code. Signed-off-by: Matthias Brugger Link: https://lore.kernel.org/r/20200608095217.21162-2-matthias.bgg@kernel.org Signed-off-by: Greg Kroah-Hartman

device.h: move 'struct driver' stuff out to device/driver.h

2019-12-16T09:11:16+00:00

device.h has everything and the kitchen sink when it comes to struct device things, so split out the struct driver things things to a separate .h file to make things easier to maintain and manage over time. Cc: "Rafael J. Wysocki" Cc: Suzuki K Poulose Cc: Saravana Kannan Cc: Heikki Krogerus Link: https://lore.kernel.org/r/20191209193303.1694546-7-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver_find_device: Unify the match function with class_find_device()

2019-06-24T03:22:31+00:00

The driver_find_device() accepts a match function pointer to filter the devices for lookup, similar to bus/class_find_device(). However, there is a minor difference in the prototype for the match parameter for driver_find_device() with the now unified version accepted by {bus/class}_find_device(), where it doesn't accept a "const" qualifier for the data argument. This prevents us from reusing the generic match functions for driver_find_device(). For this reason, change the prototype of the driver_find_device() to make the "match" parameter in line with {bus/class}_find_device() and adjust its callers to use the const qualifier. Also, we could now promote the "data" parameter to const as we pass it down as a const parameter to the match functions. Cc: Corey Minyard Cc: Russell King Cc: Thierry Reding Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Will Deacon Cc: Joerg Roedel Cc: Peter Oberparleiter Cc: Sebastian Ott Cc: David Airlie Cc: Daniel Vetter Cc: Nehal Shah Cc: Shyam Sundar S K Cc: Lee Jones Cc: Christian Borntraeger Signed-off-by: Suzuki K Poulose Signed-off-by: Greg Kroah-Hartman

driver-core: return EINVAL error instead of BUG_ON()

2018-05-25T16:18:45+00:00

I triggerd the BUG_ON() in driver_register() when booting a domU Xen domain. Since there was no contextual information logged, I needed to attach kgdb to determine the culprit (the wmi-bmof driver in my case). The BUG_ON() was added in commit f48f3febb2cb ("driver-core: do not register a driver with bus_type not registered"). Instead of running into a BUG_ON() we print an error message identifying the, likely faulty, driver but continue booting. Signed-off-by: Florian Schmaus Signed-off-by: Greg Kroah-Hartman

drivers: base: omit redundant interations

2017-12-18T15:47:27+00:00

When error happens, these interators return the error, no interation should be continued, so make the change for getting out of while immediately. Signed-off-by: Gimcuan Hui Signed-off-by: Greg Kroah-Hartman