From: Mario Limonciello <superm1@kernel•org>
To: "Christian König" <christian.koenig@amd•com>,
"Bert Karwatzki" <spasswolf@web•de>,
linux-kernel@vger•kernel.org
Cc: linux-next@vger•kernel.org, amd-gfx@lists•freedesktop.org,
Alex Deucher <alexander.deucher@amd•com>
Subject: Re: [PATCH] Revert "drm/amd: Check if ASPM is enabled from PCIe subsystem"
Date: Mon, 2 Feb 2026 10:11:02 -0600 [thread overview]
Message-ID: <2a3a3d4f-efa2-46e5-8fee-f51cf12812a9@kernel.org> (raw)
In-Reply-To: <b978d83d-3bd2-4ef0-8a2c-eb756a880fa4@amd.com>
On 2/2/26 8:35 AM, Christian König wrote:
> On 2/2/26 15:25, Mario Limonciello wrote:
>> On 1/31/26 6:24 PM, Bert Karwatzki wrote:
>>> This reverts commit 7294863a6f01248d72b61d38478978d638641bee.
>>>
>>> This commit was erroneously applied again after commit 0ab5d711ec74
>>> ("drm/amd: Refactor `amdgpu_aspm` to be evaluated per device")
>>> removed it, leading to very hard to debug crashes, when used with a system with two
>>> AMD GPUs of which only one supports ASPM.
>>>
>>> Link: https://lore.kernel.org/linux-acpi/20251006120944.7880-1-spasswolf@web.de/
>>> Link: https://github.com/acpica/acpica/issues/1060
>>> Fixes: 0ab5d711ec74 ("drm/amd: Refactor `amdgpu_aspm` to be evaluated per device")
>>>
>>> Signed-off-by: Bert Karwatzki <spasswolf@web•de>
>>> ---
>>
>> Amazing detective work, thanks so much.
>>
>> This added the code initially:
>> cba07cce39ace drm/amd: Check if ASPM is enabled from PCIe subsystem
>>
>> This effectively removed it:
>> 0ab5d711ec74d drm/amd: Refactor `amdgpu_aspm` to be evaluated per device
>>
>> This was the accidental re-apply:
>> 7294863a6f012 drm/amd: Check if ASPM is enabled from PCIe subsystem
>>
>> It looks like this as right on the edge of the 5.17-rc6 and 5.18-rc1.
>> I think drm-fixes-2022-02-25 and amd-drm-next-5.18-2022-02-25 ended up with different content.
>>
>> Nonethless this is the correct change and I've applied it to amd-staging-drm-next.
>>
>> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel•org>
>
> Reviewed-by: Christian König <christian.koenig@amd•com>
>
> There is just one major question left: Why is disabling ASPM causing problems?
>
My theory is that it's a mismatch of PCIe core and AMDGPU. IE if the
PCIe core thinks it's enabled but amdgpu thinks it is disabled can hit
some corner scenarios.
> I mean we had tons of problems with ASPM before, but only by accidentally enabling it and never accidentally disabling it.
>
> IIRC we even suggested to disable ASPM as possible workaround.
>
> Thanks,
> Christian.
>
>>
>>> drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 3 ---
>>> 1 file changed, 3 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>> index d6d0a6e34c6b..95d26f086d54 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>> @@ -2405,9 +2405,6 @@ static int amdgpu_pci_probe(struct pci_dev *pdev,
>>> return -ENODEV;
>>> }
>>> - if (amdgpu_aspm == -1 && !pcie_aspm_enabled(pdev))
>>> - amdgpu_aspm = 0;
>>> -
>>> if (amdgpu_virtual_display ||
>>> amdgpu_device_asic_has_dc_support(pdev, flags & AMD_ASIC_MASK))
>>> supports_atomic = true;
>>
>
next prev parent reply other threads:[~2026-02-02 16:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-01 0:24 [PATCH] Revert "drm/amd: Check if ASPM is enabled from PCIe subsystem" Bert Karwatzki
2026-02-02 14:25 ` Mario Limonciello
2026-02-02 14:35 ` Christian König
2026-02-02 16:11 ` Mario Limonciello [this message]
2026-02-02 16:43 ` Bert Karwatzki
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