Hello folks, I'm currently trying to understand whether xf86EnableIO / hwEnableIO() on Linux (hw/xfree86/os-support/linux/lnx_video.c) is still needed.
Still struggling with clearly understanding what it's /actually/ supposed to mean - even what's the exact definition of "IO" here. On PPC, it just checks whether it can mmap() a piece of /dev/mem, but not doing anything else (it's retval is stored in xorgHWAccess ... strange: vmmouse driver calls xf86EnableIO() if xorgHWAccess==0 and then unconditionally sets it to one - is that really correct ?) On a bunch of other archs (i386, x86-64, ia64, alpha) it calls ioperm() in order to enable IO ports. On alpha, it has another special logic looking for the IO port ranges of keyboard and timer (from /proc/ioports) and calls ioperm() on these ranges, too. Haven't looked at on other OS'es yet ... That's raising a bunch of questions: Are semantics of xf86EnableIO() really portable or does caller need extra knowledge what it means in specific context (OS, arch, ...) ? Do we stil need that special logic for keyboard IO - more precisely should even try to directly access some specific keyboard device directly, while Linux already has generic subsys for that ? Is this really still used ? Does that even still work ? Do we even need that ioperm() calls at all ? And if so, wouldn't it be better off in individual drivers ? thanks, --mtx -- --- Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren GPG/PGP-Schlüssel zu. --- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering i...@metux.net -- +49-151-27565287
