From 9f0346dcbea363787186c94ef94dd01aaa215afa Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 5 Sep 2026 11:59:05 -0700 Subject: Merge tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core Pull driver core fixes from Danilo Krummrich: - Fix kernfs listxattr() not returning security xattr names (e.g. SELinux labels) when the kernfs node has no allocated kernfs_iattrs - Fix silent truncation of IRQ vector indices in the Rust PCI abstractions - Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is disabled instead of silently enabling extra kernel functionality - Russ Weight is retiring from kernel development; update the Firmware Loader sysfs contact to the driver-core mailing list, add a CREDITS entry for Firmware Upload, and update MAINTAINERS accordingly * tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: MAINTAINERS: Remove Russ Weight from Firmware Loader CREDITS: Add CREDITS entry for Firmware Upload firmware_loader: Change contact for sysfs nodes rust: pci: reject IRQ vector indices that do not fit in u32 kernfs: preserve security xattrs without allocating iattrs drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF --- Documentation/driver-api/firmware/introduction.rst | 27 ++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 Documentation/driver-api/firmware/introduction.rst (limited to 'Documentation/driver-api/firmware/introduction.rst') diff --git a/Documentation/driver-api/firmware/introduction.rst b/Documentation/driver-api/firmware/introduction.rst new file mode 100644 index 000000000..211cb44eb --- /dev/null +++ b/Documentation/driver-api/firmware/introduction.rst @@ -0,0 +1,27 @@ +============ +Introduction +============ + +The firmware API enables kernel code to request files required +for functionality from userspace, the uses vary: + +* Microcode for CPU errata +* Device driver firmware, required to be loaded onto device + microcontrollers +* Device driver information data (calibration data, EEPROM overrides), + some of which can be completely optional. + +Types of firmware requests +========================== + +There are two types of calls: + +* Synchronous +* Asynchronous + +Which one you use vary depending on your requirements, the rule of thumb +however is you should strive to use the asynchronous APIs unless you also +are already using asynchronous initialization mechanisms which will not +stall or delay boot. Even if loading firmware does not take a lot of time +processing firmware might, and this can still delay boot or initialization, +as such mechanisms such as asynchronous probe can help supplement drivers. -- cgit v1.3.1