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commit f87812284172a9809820d10143b573d833cd3f75 upstream. Reproducing bug report here: After hibernating and resuming, DPM is not enabled. This remains the case even if you test hibernate using the steps here: https://www.kernel.org/doc/html/latest/power/basic-pm-debugging.html I debugged the problem, and figured out that in the file hardwaremanager.c, in the function, phm_enable_dynamic_state_management(), the check 'if (!hwmgr->pp_one_vf && smum_is_dpm_running(hwmgr) && !amdgpu_passthrough(adev) && adev->in_suspend)' returns true for the hibernate case, and false for the suspend case. This means that for the hibernate case, the AMDGPU driver doesn't enable DPM (even though it should) and simply returns from that function. In the suspend case, it goes ahead and enables DPM, even though it doesn't need to. I debugged further, and found out that in the case of suspend, for the CIK/Hawaii GPUs, smum_is_dpm_running(hwmgr) returns false, while in the case of hibernate, smum_is_dpm_running(hwmgr) returns true. For CIK, the ci_is_dpm_running() function calls the ci_is_smc_ram_running() function, which is ultimately used to determine if DPM is currently enabled or not, and this seems to provide the wrong answer. I've changed the ci_is_dpm_running() function to instead use the same method that some other AMD GPU chips do (e.g Fiji), which seems to read the voltage controller. I've tested on my R9 390 and it seems to work correctly for both suspend and hibernate use cases, and has been stable so far. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=208839 Signed-off-by: Sandeep Raghuraman <sandy.8925@gmail.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.