On Thu, Jul 14, 2016 at 08:53:06PM -0400, Rich Felker wrote: > mmap of uio devices does not seem to work without further > nommu-specific support, but interrupt handling already works, and > userspace drivers for nommu systems can simply use physical mmio > addresses from userspace directly anyway without mmap. > > Signed-off-by: Rich Felker <dal...@libc.org> > --- > > I don't particularly expect this to be accepted upstream as-is, but > since we're actually trying to use the UIO subsystem on nommu (J2), > I'd like to start a discussion of what an acceptable patch would > entail. > > The uio_pdrv_genirq driver was tested on J2 with this patch and > interrupt handling works as expected. > > drivers/uio/Kconfig | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig > index 52c98ce..387b2bb 100644 > --- a/drivers/uio/Kconfig > +++ b/drivers/uio/Kconfig > @@ -1,6 +1,5 @@ > menuconfig UIO > tristate "Userspace I/O drivers" > - depends on MMU
This doesn't seem to do much, don't you need to modify uio-specific drivers? Or given that the core uio code doesn't rely on mmu, is this safe? thanks, greg k-h