From 7e61560628d17ea6b1d8ee370f6d42694cff8758 Mon Sep 17 00:00:00 2001 From: Ulises Mendez Martinez Date: Fri, 4 Sep 2026 15:07:09 +0000 Subject: objtool: Validate disassembler headers in libopcodes probe commit 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") tested for libopcodes availability by linking a test snippet with a forward declaration of disassemble_init_for_target(). However, testing symbol linkage with an extern declaration only verifies the presence of the library (.so/.a) and bypasses checking for development headers (binutils-dev). On systems where libopcodes is present without development headers installed, the probe succeeds, enabling BUILD_DISAS. Subsequent compilation of objtool then fails: fatal error: 'bfd.h' file not found 113 | #include Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring any sysroot or include flags specified for the host compiler. Fix this by including and directly in the test snippet, passing $(HOSTCFLAGS) so host compiler options are respected, and defining PACKAGE="objtool" to satisfy the configuration check in . Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check") Reported-by: Alice Ryhl Assisted-by: Antigravity:Gemini-Next Signed-off-by: Ulises Mendez Martinez Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com Signed-off-by: Josh Poimboeuf --- Documentation/driver-api/devfreq.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 Documentation/driver-api/devfreq.rst (limited to 'Documentation/driver-api/devfreq.rst') diff --git a/Documentation/driver-api/devfreq.rst b/Documentation/driver-api/devfreq.rst new file mode 100644 index 000000000..4a0bf87a3 --- /dev/null +++ b/Documentation/driver-api/devfreq.rst @@ -0,0 +1,30 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================== +Device Frequency Scaling +======================== + +Introduction +------------ + +This framework provides a standard kernel interface for Dynamic Voltage and +Frequency Switching on arbitrary devices. + +It exposes controls for adjusting frequency through sysfs files which are +similar to the cpufreq subsystem. + +Devices for which current usage can be measured can have their frequency +automatically adjusted by governors. + +API +--- + +Device drivers need to initialize a :c:type:`devfreq_profile` and call the +:c:func:`devfreq_add_device` function to create a :c:type:`devfreq` instance. + +.. kernel-doc:: include/linux/devfreq.h +.. kernel-doc:: include/linux/devfreq-event.h +.. kernel-doc:: drivers/devfreq/devfreq.c + :export: +.. kernel-doc:: drivers/devfreq/devfreq-event.c + :export: -- cgit v1.3.1