On 04.06.2012 10:44, Lauri Kasanen wrote: > On Sun, 03 Jun 2012 12:54:30 +0200 > Christian K?nig<deathsimple at vodafone.de> wrote: > >>> This moves the pm_info file from debugfs to next to the other two power >>> files. >>> >>> Requested by several users at Phoronix. >>> >>> PS: Please CC me. Also please be gentle, it's my first step in kernel-land >>> ;) >> Hui? What should this be good for? >> >> Sysfs files are for setting driver parameters, like the power management >> method or profile currently in use. One major advantage of sysfs is the >> strict rules for a permanent and machine usable interface, for example >> it is mandatory to only specify one parameter per sysfs file. >> >> Debugfs on the other hand should be used for human readable >> informations, e.g. the printing the current clocks in a human readable >> form. Also you don't need a debug build or turn on any other debugging >> facility to get those information, just take a look under >> "sys/kernel/debug/dri/*". > I have no such dir, /sys/kernel/debug. The fact you have it means you have > CONFIG_DEBUGFS enabled and mounted. > >> So the code is actually quite valid as it is. > First, the current location is illogical, and several users have complained > about it. This info should be right next to where it is tweaked, ie right > next to power_profile and power_method. That is where it's expected to be by > users. > > Secondly, checking the clocks is absolutely not a debug operation. Therefore > requiring a debug option (CONFIG_DEBUGFS) to see this info is plain wrong.. > This info needs to be available to all users, including those on production > kernels without such debug options. > > -- > > So the issue is the location of the info, not the format. I'd be more than > happy to split it into six files (default_core_clock, current_core_clock...) > that each offer just a kHz number, just like the cpufreq scaling_cur_freq do. > Would that be preferable? Yeah, that sounds like a start, and also only register those files if the clock in question is really available, e. g. integrated chipsets doesn't have a memory clock for example.
But I have my doubts that it would be accepted easily, cause for debugfs we can pretty much pump every information in there we want, while sysfs files must maintain a more or less stable API for setting system parameters, see Documentation/sysfs-rules.txt. Christian.
