On Mon, Jun 23, 2014 at 12:07 PM, Greg KH <greg@xxxxxxxxx> wrote: > On Sun, Jun 22, 2014 at 10:12:14PM -0400, Ilia Mirkin wrote: >> On Sat, Jun 21, 2014 at 3:45 PM, Greg KH <greg@xxxxxxxxx> wrote: >> > On Sat, Jun 21, 2014 at 02:22:59PM -0400, Ilia Mirkin wrote: >> >> On Sat, Jun 21, 2014 at 2:02 PM, Pavel Machek <pavel@xxxxxx> wrote: >> >> > Hi! >> >> > >> >> > AFAICT, pstate file will contain something like >> >> > >> >> > 07: core 100 MHz memory 123 MHz * >> >> > 08: core 100-200 MHz memory 123 MHz >> >> > >> >> > ...which does not look exactly like one-value-per-file, and I'm pretty >> >> > sure userspace will get it wrong if it tries to parse it. Plus, I >> >> > don't see required documentation in Documentation/ABI. >> >> > >> >> > Should we disable it for now, so that userspace does not start >> >> > depending on it and we'll not have to maintain it forever? >> >> > >> >> > I guess better interface would be something like >> >> > >> >> > pstate/07/core_clock_min >> >> > core_clock_max >> >> > memory_clock_min >> >> > memory_clock_max >> >> > >> >> > and then pstate/active containing just the number of active state? >> >> > >> >> > Thanks, >> >> > Pavel >> >> > >> >> > PS: I have no nvidia, got the news at >> >> > >> >> > http://www.phoronix.com/scan.php?page=article&item=nouveau_try_linux316&num=2 >> >> >> >> FTR, this file has been in place since 3.13, and there was a different >> >> file before it (performance_levels), with a comparable format since >> >> much earlier (definitely 3.8, probably earlier). I think it's meant a >> >> lot more for people looking at it and echo'ing stuff to it to modify >> >> the levels (where supported), than for programs parsing it. Perhaps >> >> sysfs is the wrong place for this -- what is the right place? debugfs? >> > >> > Yes, please move it to debugfs. >> >> Could we just say that the format of this file is one-per-line of >> >> level: information-for-the-user >> >> And you can echo a level into it to switch to that level? That seems >> like a reasonable ABI to have... would be happy to throw it into a >> file somewhere... not sure where though. > > sysfs files are "one value per file", that's it. Do anything other than > that, and it can not be in sysfs, sorry. I think that's a little inconsistent. There are *tons* of files in sysfs with multiple values. For example "local_cpulist" which contains the string "0-3" for me, the per-connector "modes" file which has a list of modes supported, and a "resource" file which has a list of hex values (which probably have something to do with PCI resources?). [I purposely picked values coming from different parts of the kernel not to focus on one subsystem...] -ilia _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
