On Wed, Oct 29, 2014 at 07:22:58PM -0500, Jeff Epler wrote: > Hi. > > I am an author of LinuxCNC, a GPL'd CNC control for Linux. > > Recently we added support for userspace PCI drivers. This worked with > kernel 3.2 but doesn't with kernel 3.16. The software fails early with > Failed to open "/sys/devices/pci0000:00/.../enable" (Permission denied) > > This appears to be because our software relies on the documented > "enable" sysfs file for pci devices (Documentation/filesystem/sysfs-pci.txt) > which was (unintentionally?) changed to "enabled" in the above-named > patch: > > 5136b2da770d PCI: convert bus code to use dev_groups > ... > +static DEVICE_ATTR_RW(enabled); > ... > - __ATTR(enable, 0600, is_enabled_show, is_enabled_store), > > Are we in the LinuxCNC project wrong in thinking that stuff in /sys (and > not /sys/debug) is supposed to be a durable API/interface for userspace > to the kernel? (It must be a low-usage API if it went unnoticed for a > year :-/) Ugh, that's my fault, I made a typo and should not have renamed the sysfs file, very sorry about that. I'll work on making up a patch to fix this and get it into the stable kernels so that you don't have to have a work-around for very long. > We'll have to work around it by modifying our software (since we'd like > to work with the kernels people already have) in any case. > > Even if it is not going to be changed compatibly with older kernels, it > seems like the documentation should be updated! I'll fix it up, this was just a bug, my apologies. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
