The adev->pm.mutx is already held at the beginning of amdgpu_dpm_compute_clocks/amdgpu_dpm_enable_uvd/amdgpu_dpm_enable_vce. But on their calling path, amdgpu_display_bandwidth_update will be called and thus its sub functions amdgpu_dpm_get_sclk/mclk. They will then try to acquire the same adev->pm.mutex and deadlock will occur. By placing amdgpu_display_bandwidth_update outside of adev->pm.mutex protection(considering logically they do not need such protection) and restructuring the call flow accordingly, we can eliminate the deadlock issue. This comes with no real logics change. Fixes: 3712e7a49459 ("drm/amd/pm: unified lock protections in amdgpu_dpm.c") Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Reported-by: Arthur Marsh <arthur.marsh@internode.on.net> Link: https://lore.kernel.org/all/9e689fea-6c69-f4b0-8dee-32c4cf7d8f9c@molgen.mpg.de/ BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1957 Signed-off-by: Evan Quan <evan.quan@amd.com> Reviewed-by: Lijo Lazar <lijo.lazar@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
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.
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