From: Sandeep Raghuraman sandy.8925@gmail.com
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
--- drivers/gpu/drm/amd/powerplay/smumgr/ci_smumgr.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/amd/powerplay/smumgr/ci_smumgr.c +++ b/drivers/gpu/drm/amd/powerplay/smumgr/ci_smumgr.c @@ -2725,7 +2725,10 @@ static int ci_initialize_mc_reg_table(st
static bool ci_is_dpm_running(struct pp_hwmgr *hwmgr) { - return ci_is_smc_ram_running(hwmgr); + return (1 == PHM_READ_INDIRECT_FIELD(hwmgr->device, + CGS_IND_REG__SMC, FEATURE_STATUS, + VOLTAGE_CONTROLLER_ON)) + ? true : false; }
static int ci_smu_init(struct pp_hwmgr *hwmgr)