Re: [PATCH] PCI: fix Sapphire PCI rebar quirk

["Christian König" <christian.koenig@amd.com>]

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.

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
> Fixes: 907830b0fc9e ("PCI: Add a REBAR size quirk for Sapphire RX 5600 XT Pulse")
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Nirmoy Das <nirmoy.aiemd@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;
>