mainlining shenanigans
b56a53db4c
Clang warns (only Navi warning shown but Arcturus warns as well):
drivers/gpu/drm/amd/amdgpu/../powerplay/navi10_ppt.c:1534:4: warning:
variable 'asic_default_power_limit' is used uninitialized whenever '?:'
condition is false [-Wsometimes-uninitialized]
smu_read_smc_arg(smu, &asic_default_power_limit);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../powerplay/inc/amdgpu_smu.h:588:3: note:
expanded from macro 'smu_read_smc_arg'
((smu)->funcs->read_smc_arg? (smu)->funcs->read_smc_arg((smu), (arg)) : 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../powerplay/navi10_ppt.c:1550:30: note:
uninitialized use occurs here
smu->default_power_limit = asic_default_power_limit;
^~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../powerplay/navi10_ppt.c:1534:4: note:
remove the '?:' if its condition is always true
smu_read_smc_arg(smu, &asic_default_power_limit);
^
drivers/gpu/drm/amd/amdgpu/../powerplay/inc/amdgpu_smu.h:588:3: note:
expanded from macro 'smu_read_smc_arg'
((smu)->funcs->read_smc_arg? (smu)->funcs->read_smc_arg((smu), (arg)) : 0)
^
drivers/gpu/drm/amd/amdgpu/../powerplay/navi10_ppt.c:1517:35: note:
initialize the variable 'asic_default_power_limit' to silence this
warning
uint32_t asic_default_power_limit;
^
= 0
1 warning generated.
As the code is currently written, if read_smc_arg were ever NULL, arg
would fail to be initialized but the code would continue executing as
normal because the return value would just be zero.
There are a few different possible solutions to resolve this class
of warnings which have appeared in these drivers before:
1. Assume the function pointer will never be NULL and eliminate the
wrapper macros.
2. Have the wrapper macros initialize arg when the function pointer is
NULL.
3. Have the wrapper macros return an error code instead of 0 when the
function pointer is NULL so that the callsites can properly bail out
before arg can be used.
4. Initialize arg at the top of its function.
Number four is the path of least resistance right now as every other
change will be driver wide so do that here. I only make the comment
now as food for thought.
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.