javier Martin <javier.martin@xxxxxxxxxxxxxxxxx> writes: > On 2 September 2011 19:14, Kevin Hilman <khilman@xxxxxx> wrote: >> javier Martin <javier.martin@xxxxxxxxxxxxxxxxx> writes: >> >>> On 2 September 2011 08:05, Jarkko Nikula <jarkko.nikula@xxxxxxxxxx> wrote: >>>> Other usual things to check that display is off (echo 1 > >>>> /sys/class/graphics/fb0/blank) and no cable to musb/otg port. >>>> >>>> Haven't tried myself with recent kernel but does EHCI and hub on XM let to >>>> idle cpu at all? At least on one board having on-board hub I had to disable >>>> or unload ehci module in order to hit the retention. >>>> >>> >>> I've checked that too and I've even disabled USB support in the kernel >>> just to be sure. But still nothing: >>> >>> root@beagleboard:~# powertop -d -t 100 >>> PowerTOP 1.12 (C) 2007, 2008 Intel Corporation >>> >>> Collecting data for 100 seconds >>> >>> >>> Cn Avg residency >>> C0 (cpu running) ( 0.0%) >>> C0 58.5ms (100.0%) >>> C1 0.0ms ( 0.0%) >>> C2 0.0ms ( 0.0%) >>> C3 0.0ms ( 0.0%) >>> C4 0.0ms ( 0.0%) >>> C5 0.0ms ( 0.0%) >>> C6 0.0ms ( 0.0%) >>> >>> Even when CPU has been idle 100% of the time it doesn't hit any state >>> deeper than C0. >> >> Did you allow the UARTs to idle: > > Yes I did: > root@beagleboard:/sys/devices/system/cpu/cpu0/cpuidle# echo 5 > > /sys/devices/platform/omap/omap_uart.0/sleep_timeout > root@beagleboard:/sys/devices/system/cpu/cpu0/cpuidle# echo 5 > > /sys/devices/platform/omap/omap_uart.1/sleep_timeout > root@beagleboard:/sys/devices/system/cpu/cpu0/cpuidle# echo 5 > > /sys/devices/platform/omap/omap_uart.2/sleep_timeout > root@beagleboard:/sys/devices/system/cpu/cpu0/cpuidle# echo 5 > > /sys/devices/platform/omap/omap_uart.3/sleep_timeout > > [ 65.853820] omap_device: omap_uart.3: new worst case activate > latency 0: 30517 > [ 65.944366] omap_device: omap_uart.2: new worst case deactivate > latency 0: 30517 > > >> # UART timeouts: omap-serial (4th UART only on OMAP36xx and OMAP4) >> echo 5 > /sys/devices/platform/omap/omap_uart.0/sleep_timeout >> echo 5 > /sys/devices/platform/omap/omap_uart.1/sleep_timeout >> echo 5 > /sys/devices/platform/omap/omap_uart.2/sleep_timeout >> echo 5 > /sys/devices/platform/omap/omap_uart.3/sleep_timeout >> >> I just tested this using today's linux-omap master branch (+ merged >> v3.1-rc4 which includes a fix for a bootup problem.) >> >> I booted my Beagle XM with a busybox rootfs on MMC and it worked fine >> for me. >> >> I don't have powertop on the rootfs, but I manually dumped the sysfs >> files that powertop reads, so I can see the state times. >> >> After allowing the UARTs to idle, I see: >> >> # cd /sys/devices/system/cpu/cpu0 >> /sys/devices/system/cpu/cpu0/cpuidle # cat state?/time >> 43531831 >> 8997 >> 157215 >> 0 >> 3467925 >> 0 >> 0 > > OK, I've just tried with the same kernel as you did (linux-omap master > + v3.1-rc4 merge) and I can't get any other state than 0: > Just one question. Do you access the shell through UART? Yes. > What I do is waiting for 20 seconds to allow the UART to suspend and > then see state reports. Then I suspect your userspace is keeping the system active. Can you try to just boot a minimal userspace (e.g. append init=/bin/sh to your kernel command line, or use a basic busybox rootfs.) Keivn -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
