On Thu, May 22, 2025 at 06:19:56PM +0200, Niklas Cassel wrote:
> As you know the reset_slot() callback patches were merged recently.
>
> Wilfred and I (mostly Wilfred), have been debugging DMA issues after the
> reset_slot() callback has been invoked. The issue is reproduced when MPS
> configuration is set to performance, but might be applicable for other
> MPS configurations as well. The problem appears to be that reset_slot()
> feature does not respect/restore the MPS configuration.
The Device Control register (and thus the MPS setting) is saved via:
pci_save_state()
pci_save_pcie_state()
So either you're missing a call to pci_restore_state() after reset,
or you're missing a call to pci_save_state() after changing MPS,
or MPS is somehow overwritten after pci_restore_state().
Which one is it?
Thanks,
Lukas
