Preeti U Murthy <pre...@linux.vnet.ibm.com> writes: > On 01/28/2015 02:45 PM, Stewart Smith wrote: >> Preeti U Murthy <pre...@linux.vnet.ibm.com> writes: >>> The device tree now exposes the residency values for different idle states. >>> Read >>> these values instead of calculating residency from the latency values. The >>> values >>> exposed in the DT are validated for optimal power efficiency. However to >>> maintain >>> compatibility with the older firmware code which does not expose residency >>> values, use default values as a fallback mechanism. While at it, handle some >>> cleanups. >> >> From a "I just merged the patch that exports these values from firmware" >> point of view, using them and falling back looks good. >> >> (I find the hardcoding of snooze in the driver a bit odd, as is the > > Snooze is the only software defined idle state, the rest are platform > specific. The first idle state is usually associated with some sort of a > polling operation and each architecture has a variant to this. This is > why we end up hard-coding this idle state in the driver as far as my > understanding goes.
At least in the PowerISA 2.07 I could only see that lowering priority would give priority to other threads in the core, I couldn't find anything saying that or 31,31,31 would end up saving any power... but I could be looking in the wrong place too. Basically, I was wanting to check that it's actually written down and architected somewhere that this is the case and it isn't something too P7/P8 specific. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
