| Message ID | 20180319095101.21155-1-bjorn@mork.no |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [LEDE-DEV] mvebu: disable CPU_IDLE as a Mamba instability workaround | expand |
On 2018-03-19 10:51, Bjørn Mork wrote: > A regression seriously affecting the Linksys WRT1900ACv1 (Mamba) was > introduced some time between the OpenWrti/LEDE v4.4 and v4.9 kernels. > The root cause has not yet been identified, despite many attempts for > more than a year. However, disabling CPU_IDLE, and implicitly CPU_PM, > has been proven to be an effective workaround. > > The symptoms on an affected system are unwanted reboots a a variable > frequency. In many cases almost immediately after boot, causing a > bootloop. This effectively disables support for Mamba on OpenWrt > with kernels > v4.4. > > Disabling CPU_IDLE for now to reenable Mamba support. > > Link: https://forum.lede-project.org/t/wrt1900acv1-reboots-kernel-4-9/2025 > Signed-off-by: Bjørn Mork <bjorn@mork.no> Please try this variant instead, which should not affect unrelated devices: https://git.openwrt.org/0142d447bc02922369c363de6510e76848943e9a It's in my staging tree at https://git.openwrt.org/?p=openwrt/staging/nbd.git;a=summary Thanks, - Felix
Felix Fietkau <nbd@nbd.name> writes: > On 2018-03-19 10:51, Bjørn Mork wrote: >> A regression seriously affecting the Linksys WRT1900ACv1 (Mamba) was >> introduced some time between the OpenWrti/LEDE v4.4 and v4.9 kernels. >> The root cause has not yet been identified, despite many attempts for >> more than a year. However, disabling CPU_IDLE, and implicitly CPU_PM, >> has been proven to be an effective workaround. >> >> The symptoms on an affected system are unwanted reboots a a variable >> frequency. In many cases almost immediately after boot, causing a >> bootloop. This effectively disables support for Mamba on OpenWrt >> with kernels > v4.4. >> >> Disabling CPU_IDLE for now to reenable Mamba support. >> >> Link: https://forum.lede-project.org/t/wrt1900acv1-reboots-kernel-4-9/2025 >> Signed-off-by: Bjørn Mork <bjorn@mork.no> > Please try this variant instead, which should not affect unrelated devices: > https://git.openwrt.org/0142d447bc02922369c363de6510e76848943e9a > > It's in my staging tree at > https://git.openwrt.org/?p=openwrt/staging/nbd.git;a=summary Works for me. Thanks. Much better solution. Bjørn
Bjørn Mork wrote: > Felix Fietkau <nbd@nbd.name> writes: > > >> On 2018-03-19 10:51, Bjørn Mork wrote: >> >>> A regression seriously affecting the Linksys WRT1900ACv1 (Mamba) was >>> introduced some time between the OpenWrti/LEDE v4.4 and v4.9 kernels. >>> The root cause has not yet been identified, despite many attempts for >>> more than a year. However, disabling CPU_IDLE, and implicitly CPU_PM, >>> has been proven to be an effective workaround. >>> >>> The symptoms on an affected system are unwanted reboots a a variable >>> frequency. In many cases almost immediately after boot, causing a >>> bootloop. This effectively disables support for Mamba on OpenWrt >>> with kernels > v4.4. >>> >>> Disabling CPU_IDLE for now to reenable Mamba support. >>> >>> Link: https://forum.lede-project.org/t/wrt1900acv1-reboots-kernel-4-9/2025 >>> Signed-off-by: Bjørn Mork <bjorn@mork.no> >>> >> Please try this variant instead, which should not affect unrelated devices: >> https://git.openwrt.org/0142d447bc02922369c363de6510e76848943e9a >> >> It's in my staging tree at >> https://git.openwrt.org/?p=openwrt/staging/nbd.git;a=summary >> > > Works for me. Thanks. Much better solution. > Confirmed fixing the reboot problem on another Mamba. Regards, Zoltan H
diff --git a/target/linux/mvebu/config-4.14 b/target/linux/mvebu/config-4.14 index 5286bf9b8314..78bed5b32f7b 100644 --- a/target/linux/mvebu/config-4.14 +++ b/target/linux/mvebu/config-4.14 @@ -54,7 +54,6 @@ CONFIG_ARM_HEAVY_MB=y CONFIG_ARM_L1_CACHE_SHIFT=6 CONFIG_ARM_L1_CACHE_SHIFT_6=y # CONFIG_ARM_LPAE is not set -CONFIG_ARM_MVEBU_V7_CPUIDLE=y CONFIG_ARM_PATCH_IDIV=y CONFIG_ARM_PATCH_PHYS_VIRT=y CONFIG_ARM_THUMB=y @@ -103,11 +102,8 @@ CONFIG_CPU_FREQ_STAT=y CONFIG_CPU_HAS_ASID=y # CONFIG_CPU_HOTPLUG_STATE_CONTROL is not set # CONFIG_CPU_ICACHE_DISABLE is not set -CONFIG_CPU_IDLE=y -CONFIG_CPU_IDLE_GOV_LADDER=y CONFIG_CPU_PABRT_V7=y CONFIG_CPU_PJ4B=y -CONFIG_CPU_PM=y CONFIG_CPU_RMAP=y CONFIG_CPU_THERMAL=y CONFIG_CPU_THUMB_CAPABLE=y
A regression seriously affecting the Linksys WRT1900ACv1 (Mamba) was introduced some time between the OpenWrti/LEDE v4.4 and v4.9 kernels. The root cause has not yet been identified, despite many attempts for more than a year. However, disabling CPU_IDLE, and implicitly CPU_PM, has been proven to be an effective workaround. The symptoms on an affected system are unwanted reboots a a variable frequency. In many cases almost immediately after boot, causing a bootloop. This effectively disables support for Mamba on OpenWrt with kernels > v4.4. Disabling CPU_IDLE for now to reenable Mamba support. Link: https://forum.lede-project.org/t/wrt1900acv1-reboots-kernel-4-9/2025 Signed-off-by: Bjørn Mork <bjorn@mork.no> --- target/linux/mvebu/config-4.14 | 4 ---- 1 file changed, 4 deletions(-)