On Thu, 2017-09-07 at 17:16 +1000, Benjamin Herrenschmidt wrote: > On Wed, 2017-09-06 at 15:20 +0000, Joakim Tjernlund wrote: > > Having problems to mmap PCI UIO devices and stumbeled over this page: > > http://billfarrow.blogspot.se/2010/09/userspace-access-to-pci-memory.html > > it claims some adjustments are needed for UIO mmap over PCI to work. > > These are #if 0 ATM and trying to enable them fails build. > > > > Can this be fixed to at least build again ? > > The reason for having #if 0 in the first place appears to be old X servers, > > is that still true? Can the special casing be removed now? > > This article seems out of date... I *think* things should work without > change by just mmap'ing the appropriate sysfs files. I'm not sure why > the author thought that had to be ifdef'ed out...
Isn't that what the article is doing(mmaping sysfs files)? And the article author is #ifdefing it back, not out. > > Let me know if you have problems. Sure, we still are looking > > As far as I know, the generic code will call pci_resource_to_user() > which on powerpc will return a physical address that already includes > the offset, which is why we don't later add it. > > Now we could probably tear all that out and use the new generic code > instead as I *think* X has (very) long been fixed but I'd have to spend > some time triple checking and testing on old HW which I don't have the > bandwidth for right now. Could you fixup the code which is now #if 0 ? I wan't to test the difference and I not sure how to fix the build problem after changing those two #if 0 to #if 1 Even better if they could be a CONFIG option instead. Jocke
