[lkml]   [2015]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC PATCH 0/4] mmc: sdhci: Support maximum DMA latency request via PM QoS
> 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.

Len Brown, Intel Open Source Technology Center

 \ /
  Last update: 2015-04-01 22:41    [W:0.138 / U:4.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site