Messages in this thread | | | Date | Wed, 1 Apr 2015 15:59:10 -0400 | Subject | Re: [RFC PATCH 0/4] mmc: sdhci: Support maximum DMA latency request via PM QoS | From | Len Brown <> |
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> Ad hoc testing with Lenovo Thinkpad 10 showed a stress > test could run for at least 24 hours with the patches, > compared to less than an hour without.
There is a patch in linux-next to delete C1E from BYT, since it is problematic on multiple platforms. I don't suppose that just disabling that state without disabling C6 is sufficient to fix the Thinkpad 10? (I'm betting not, but it can't hurt to try -- you can use the "disable" attribute for the state in /sys/devices/system/cpu/cpu*/cpuidle/stateN)
I think your choice of the PM_QOS sub-system here is the right one, and that your selection of 20usec threshold is also a good choice for what you want to do -- though on non-intel_idle machine somplace, there may be some ACPI BIOS _CST with random number for C6 latency.
It would be interesting to see how your C6 residency (turbostat --debug will show this to you) and your battery life are changed by disabling C6 during MMC activity.
cheers, Len Brown, Intel Open Source Technology Center
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