[PATCH] PCI: fix Sapphire PCI rebar quirk

[Lazar, Lijo]

On 2/18/2025 1:33 PM, Christian König wrote:
> Am 17.02.25 um 17:04 schrieb Mario Limonciello:
>> On 2/17/2025 10:00, Alex Deucher wrote:
>>> On Mon, Feb 17, 2025 at 10:45 AM Alex Deucher <alexdeucher at gmail.com> wrote:
>>>>
>>>> On Mon, Feb 17, 2025 at 10:38 AM Christian König
>>>> <christian.koenig at amd.com> wrote:
>>>>>
>>>>> Am 17.02.25 um 16:10 schrieb Alex Deucher:
>>>>>> There was a quirk added to add a workaround for a Sapphire
>>>>>> RX 5600 XT Pulse.  However, the quirk only checks the vendor
>>>>>> ids and not the subsystem ids.  The quirk really should
>>>>>> have checked the subsystem vendor and device ids as now
>>>>>> this quirk gets applied to all RX 5600 and it seems to
>>>>>> cause problems on some Dell laptops.  Add a subsystem vendor
>>>>>> id check to limit the quirk to Sapphire boards.
>>>>>
>>>>> That's not correct. The issue is present on all RX 5600 boards, not just the Sapphire ones.
>>>>
>>>> I suppose the alternative would be to disable resizing on the
>>>> problematic DELL systems only.
>>>
>>> How about this attached patch instead?
>>
>> JFYI Typo in the commit message:
>>
>> s,casused,caused,
> 
> With that fixed feel free to add my rb. It's just that the Dell systems are unstable even without the resizing.
> 
> The resizing just makes it more likely to hit the issue because ti massively improves performance on the RX 5600 boards.
> 

As a workaround, from the thread, the most reliable one seems to be to
disable runpm on the device.

Thanks,
Lijo

> Regards,
> Christian.
> 
>>
>>>
>>> Alex
>>>
>>>>
>>>>>
>>>>> The problems with the Dell laptops are most likely the general instability of the RX 5600 again which this quirk just make more obvious because of the performance improvement.
>>>>>
>>>>> Do you have a specific bug report for the Dell laptops?
>>>>>
>>>>> Regards,
>>>>> Christian.
>>>>>
>>>>>>
>>>>>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/1707
>>>>
>>>> ^^^ this bug report
>>>>
>>>> Alex
>>>>
>>>>
>>>>>> Fixes: 907830b0fc9e ("PCI: Add a REBAR size quirk for Sapphire RX 5600 XT Pulse")
>>>>>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>>>>>> Cc: Christian König <christian.koenig at amd.com>
>>>>>> Cc: Bjorn Helgaas <bhelgaas at google.com>
>>>>>> Cc: Nirmoy Das <nirmoy.aiemd at gmail.com>
>>>>>> ---
>>>>>>   drivers/pci/pci.c | 1 +
>>>>>>   1 file changed, 1 insertion(+)
>>>>>>
>>>>>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>>>>>> index 225a6cd2e9ca3..dec917636974e 100644
>>>>>> --- a/drivers/pci/pci.c
>>>>>> +++ b/drivers/pci/pci.c
>>>>>> @@ -3766,6 +3766,7 @@ u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar)
>>>>>>
>>>>>>        /* Sapphire RX 5600 XT Pulse has an invalid cap dword for BAR 0 */
>>>>>>        if (pdev->vendor == PCI_VENDOR_ID_ATI && pdev->device == 0x731f &&
>>>>>> +         pdev->subsystem_vendor == 0x1da2 &&
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>            bar == 0 && cap == 0x700)
>>>>>>                return 0x3f00;
>>>>>>
>>>>>
>>
>