Hi On 10.06.2020 16:02, Krzysztof Kozlowski wrote: > On Wed, Jun 10, 2020 at 02:18:12PM +0100, Lukasz Luba wrote: >> Hi Krzysztof, Bartek, >> >> I recall that you have been working on some cpuidle code for Exynos(4?). >> >> I have a question regarding CPUIdle driver for Odroid XU4. >> I use the board with LISA tests for EAS, but missing at >> least idle state 0 cause errors (please see the log below). >> >> Currently the system does not report any idle driver and the state 0 >> is missing in: /sys/devices/system/cpu/cpu0/cpuidle/state0/ > The state 0 long time ago was WFI. It was kind of meaningless so it it > was dropped. > >> I am using driver CONFIG_ARM_BIG_LITTLE_CPUIDLE but the >> boot stops silently while trying to init the cpu idle devices in there. >> I carry on with a workaround that just removes idle state[1] and set >> state_count=1 in the big and little structures. > Try earlyprintk. > > In general, the big-little cpuidle driver should work... or rather: long > time ago it was working. It requires proper support from early stages > (BL1, secure monitor) but this should be already in standard Odroid. > > I just saw there: > /* Start at index 1, index 0 standard WFI */ > so maybe it was not updated properly to removal of WFI? > > I think no one uses this driver so it might be not well tested and not > that useful. I think it never worked on Odroid XU3/XU4. Afair it was developed on PeachPi Chromebook, which use different bootloader (and doesn't use trustzone). Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
