On Wed, May 26, 2021 at 08:12:04PM -0500, stuart hayes wrote: > ... > I made the patch because it was causing the config space for a downstream > port to not get restored when a DPC event occurred, and all the NVMe drives > under it disappeared. I found that myself, though--I'm not aware of anyone > else reporting the issue. This niggles at me. IIUC the problem you're reporting is that portdrv didn't claim a port because portdrv incorrectly assumed the port supported bandwidth notification interrupts. That's all fine, and I think this is a good fix. But why should it matter whether portdrv claims the port? What if CONFIG_PCIEPORTBUS isn't even enabled? I guess CONFIG_PCIE_DPC wouldn't be enabled then either. In your situation, you have CONFIG_PCIEPORTBUS=y and (I assume) CONFIG_PCIE_DPC=y. I guess you must have two levels of downstream ports, e.g., Root Port -> Switch Upstream Port -> Switch Downstream Port -> NVMe and portdrv claimed the Root Port and you enabled DPC there, but it didn't claim the Switch Downstream Port? The failure to restore config space because portdrv didn't claim the port seems wrong to me. Bjorn
