[REGRESSION] drm/amd/display: Radeon 840M/860M: bisected suspend crash

[Mario Limonciello]

On 6/17/2025 6:42 PM, Alex Hung wrote:
> Hi,
> 
> Thanks for reporting. Can you please create a bug at https:// 
> gitlab.freedesktop.org/drm/amd/-/issues/ for issue tracking and log 
> collection.
> 
> On 6/12/25 08:08, ggo at tuxedocomputers.com wrote:
>> Hi,
>>
>> I have discovered that two small form factor desktops with Ryzen AI 7
>> 350 and Ryzen AI 5 340 crash when woken up from suspend. I can see how
>> the LED on the USB mouse is switched on when I trigger a resume via
>> keyboard button, but the display remains black. The kernel also no
>> longer responds to Magic SysRq keys in this state.
>>
>> The problem affects all kernels after merge b50753547453 (v6.11.0). But
>> this merge only adds PCI_DEVICE_ID_AMD_1AH_M60H_ROOT with commit
>> 59c34008d (necessary to trigger this bug with Ryzen AI CPU).
>> I cherry-picked this commit and continued searching. Which finally led
>> me to commit f6098641d3e - drm/amd/display: fix s2idle entry for DCN3.5+
>>
>> If I remove the code, which has changed somewhat in the meantime, then
>> the suspend works without any problems. See the following patch.
>>
>> Regards,
>> Georg
>>
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> index d3100f641ac6..76204ae70acc 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -3121,9 +3121,6 @@ static int dm_suspend(struct amdgpu_ip_block
>> *ip_block)
>>
>>       dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D3);
>>
>> -    if (dm->dc->caps.ips_support && adev->in_s0ix)
>> -        dc_allow_idle_optimizations(dm->dc, true);
>> -
>>       dc_dmub_srv_set_power_state(dm->dc->ctx->dmub_srv,
>> DC_ACPI_CM_POWER_STATE_D3);
>>
>>       return 0;
>>
> 
> 

That patch you did is basically blocking hardware sleep.  I wouldn't 
call it a solution.

If you haven't already; please use 
https://git.kernel.org/pub/scm/linux/kernel/git/superm1/amd-debug-tools.git/about/ 
to triage this issue.  It will flag the most common things that are hard 
to diagnose without knowledge.

If that doesn't flag anything, please reproduce on a mainline kernel 
(6.15.y or 6.16-rcX) and then file a bug as Alex suggested.  Attach the 
report you generated from the tool there.