On Mon, Jun 06, 2016 at 02:59:47PM +0000, Koehrer Mathias (ETAS/ESW5) wrote: > Hi Greg, > > thanks for the response. > > > Some uio based PCI drivers (e.g. uio_cif) do not work if the assigned > > > PCI memory resources are not page aligned. > > > By using the kernel option "pci=resource_alignment" it is possible to > > > force single PCI boards to use page alignment for their memory resources. > > > However, this is fairly cumbersome if multiple of these cards are in use. > > > This patch adds another kernel option "pci=resources_page_aligned" > > > that allows to set the default alignment of PCI memory resources to be > > > page aligned. > > > Overwriting of this default alignment via "pci=resource_alignment" is > > > still possible. > > > > This seems like a very large hammer for a very specific problem with a card > > that seems to be not-in-spec (I can't find anywhere that requires resources > > to > > be "page" aligned in the PCI spec). Why not fix the firmware in these > > cards? > The issue is not the firmware. The issue is that the Linux uio driver (here: > uio_cif) > does not work as uio_mmap() -> uio_mmap_physical() does not do a mmap > on physical memory that is not page aligned...
Then why not fix the uio_cif driver? greg k-h
