On Thu, Aug 08, 2024 at 04:28:50PM -0400, Stewart Hildebrand wrote: > On 8/8/24 15:28, Bjorn Helgaas wrote: > > On Wed, Aug 07, 2024 at 11:17:12AM -0400, Stewart Hildebrand wrote: > >> Devices with alignment specified will lose their alignment in cases when > >> the bridge resources have been released, e.g. due to insufficient bridge > >> window size. Restore the alignment. > > > > I guess this fixes a problem when the user has specified > > "pci=resource_alignment=..." and we've decided to release and > > reallocate a bridge window? Just looking for a bit more concrete > > description of what this problem would look like to a user. > > Yes. When alignment has been specified via pcibios_default_alignment() > or by the user with "pci=resource_alignment=...", and the bridge window > is being reallocated, the specified alignment is lost and the resource > may not be sufficiently aligned after reallocation. > > I can expand the commit description. I think a hint about where the alignment gets lost would be helpful, too. This seems like a problem users could be seeing today, even independent of the device passthrough issue that I think is the main thrust of this series. If there's a problem report or an easy way to reproduce this problem, that would be nice, too. Bjorn
