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

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Message-ID: <7775829f-b612-19dd-277b-aed2e9cca991@amd.com>
Date:   Mon, 11 Apr 2022 06:11:39 -0500
From:   "Gong, Richard" <richard.gong@....com>
To:     "Lazar, Lijo" <lijo.lazar@....com>, alexander.deucher@....com,
        christian.koenig@....com, xinhui.pan@....com, airlied@...ux.ie,
        daniel@...ll.ch
Cc:     mario.limonciello@....com, dri-devel@...ts.freedesktop.org,
        amd-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCHv2] drm/amdgpu: disable ASPM on Intel AlderLake based
 systems

Hi Lijo,

On 4/10/2022 11:15 PM, Lazar, Lijo wrote:
>
>
> On 4/9/2022 12:35 AM, Richard Gong wrote:
>> 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
>> cards as video/display output, Intel Alder Lake based systems will hang
>> during suspend/resume.
>>
>> Add extra check to disable ASPM on Intel AlderLake based systems.
>>
>> Fixes: 0064b0ce85bb ("drm/amd/pm: enable ASPM by default")
>> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1885
>> 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)
>
> If this is only for Dell systems, use DMI_SYS_VENDOR/DMI_PRODUCT_NAME 
> to identify the platform information from SMBIOS.
Not sure, the report issue was originally for Dell system but may occur 
with others. This is why I just check CPU info.
>
> Better to rename to aspm_support_quirk_check() or similar, and return 
> false on is_alderlake() or is_dell_xyz();
>
Ok, will rename to aspm_support_quick_check in the next versin.

> Thanks,
> Lijo
>
>> +{
>> +#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
>> +}
>> +
>>   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 ||
>>