linux-kernel - Re: [PATCHv2] drm/amdgpu: disable ASPM on Intel AlderLake based systems

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Message-ID: <45ea5705-71d6-4008-f094-1aa902e5cc41@amd.com>
Date:   Sun, 10 Apr 2022 19:27:48 -0500
From:   "Gong, Richard" <richard.gong@....com>
To:     Paul Menzel <pmenzel@...gen.mpg.de>
Cc:     mario.limonciello@....com, dri-devel@...ts.freedesktop.org,
        amd-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        alexander.deucher@....com, christian.koenig@....com,
        xinhui.pan@....com, airlied@...ux.ie, daniel@...ll.ch
Subject: Re: [PATCHv2] drm/amdgpu: disable ASPM on Intel AlderLake based
 systems

Hi Pail.

On 4/8/2022 7:19 PM, Paul Menzel wrote:
> Dear Richard,
>
>
> Thank you for your patch.
>
> Am 08.04.22 um 21:05 schrieb Richard Gong:
>> Active State Power Management (ASPM) feature is enabled since kernel 
>> 5.14.
>> There are some AMD GFX cards (such as WX3200 and RX640) that cannot be
>> used with Intel AlderLake based systems to enable ASPM. Using these GFX
>
> Alder Lake
will correct in the next version.
>
>> cards as video/display output, Intel Alder Lake based systems will hang
>> during suspend/resume.
>
> Please reflow for 75 characters per line.
>
> Also please mention the exact system you had problems with (also 
> firmware versions).
>
>>
>> Add extra check to disable ASPM on Intel AlderLake based systems.
>
> Is that a problem with Intel Alder Lake or the Dell system? Shouldn’t 
> ASPM just be disabled for the problematic cards for the Dell system. 
> You write newer cards worked fine.

There is a problem with Dell system (Dell Precision DT workstation), 
which is based on Intel Alder Lake.

ASPM works just fine on these GPU's. It's more of an issue with whether 
the underlying platform supports ASPM or not.

>
>> Fixes: 0064b0ce85bb ("drm/amd/pm: enable ASPM by default")
>> Link: 
>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.freedesktop.org%2Fdrm%2Famd%2F-%2Fissues%2F1885&amp;data=04%7C01%7Crichard.gong%40amd.com%7C6b94ff2249244c04974e08da19bea71b%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637850604066094079%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=%2FiF%2Bnwzm5RlClT%2Fv%2B0RJvmVwsc%2FiwV3jCiFq7PB84wM%3D&amp;reserved=0
>> Signed-off-by: Richard Gong <richard.gong@....com>
>> ---
>> v2: correct commit description
>>      move the check from chip family to problematic platform
>> ---
>>   drivers/gpu/drm/amd/amdgpu/vi.c | 17 ++++++++++++++++-
>>   1 file changed, 16 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c 
>> b/drivers/gpu/drm/amd/amdgpu/vi.c
>> index 039b90cdc3bc..8b4eaf54b23e 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/vi.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/vi.c
>> @@ -81,6 +81,10 @@
>>   #include "mxgpu_vi.h"
>>   #include "amdgpu_dm.h"
>>   +#if IS_ENABLED(CONFIG_X86_64)
>> +#include <asm/intel-family.h>
>> +#endif
>> +
>>   #define ixPCIE_LC_L1_PM_SUBSTATE    0x100100C6
>>   #define PCIE_LC_L1_PM_SUBSTATE__LC_L1_SUBSTATES_OVERRIDE_EN_MASK 
>> 0x00000001L
>>   #define PCIE_LC_L1_PM_SUBSTATE__LC_PCI_PM_L1_2_OVERRIDE_MASK 
>> 0x00000002L
>> @@ -1134,13 +1138,24 @@ static void vi_enable_aspm(struct 
>> amdgpu_device *adev)
>>           WREG32_PCIE(ixPCIE_LC_CNTL, data);
>>   }
>>   +static bool intel_core_apsm_chk(void)
>
> aspm
s/apsm/aspm in the next version
>
>> +{
>> +#if IS_ENABLED(CONFIG_X86_64)
>> +    struct cpuinfo_x86 *c = &cpu_data(0);
>> +
>> +    return (c->x86 == 6 && c->x86_model == INTEL_FAM6_ALDERLAKE);
>> +#else
>> +    return false;
>> +#endif
>
> Please do the check in C code and not the preprocessor.
followed the pattern with other upsteram drivers.
>
>> +}
>> +
>>   static void vi_program_aspm(struct amdgpu_device *adev)
>>   {
>>       u32 data, data1, orig;
>>       bool bL1SS = false;
>>       bool bClkReqSupport = true;
>>   -    if (!amdgpu_device_should_use_aspm(adev))
>> +    if (!amdgpu_device_should_use_aspm(adev) || intel_core_apsm_chk())
>>           return;
>>         if (adev->flags & AMD_IS_APU ||
>
>
> Kind regards,
>
> Paul

Regards,

Richard