Bug 13555

Summary: [2.8 M3 RC1] [mpc8315e-rdb] System randomly hang when running commands
Product: [Build System, Metadata & Runtime] BSPs Reporter: Yi Zhao <yi.zhao>
Component: bsps-meta-yoctoAssignee: Bruce Ashfield <bruce.ashfield>
Status: VERIFIED FIXED QA Contact: Yi Zhao <yi.zhao>
Severity: normal    
Priority: High CC: bruce.ashfield, ee.peng.yeoh, richard.purdie, ross.burton, sangeeta.jain, yi.zhao, zhe.he
Version: 3.0   
Target Milestone: 2.8 M4   
Hardware: mpc8315e-rdb   
OS: ppc   
Whiteboard:
OS type for building Yocto: --- Type of Regression: Regression (Used to work)
Verified: Documentation change: No (bug/feature does not impact docs)

Description Yi Zhao 2019-09-26 02:04:55 UTC 
Git rev: master/81f9e815d36848761a9dfa94b00ad998bb39a4a6
Image location: https://autobuilder.yocto.io/pub/releases/yocto-2.8_M3.rc1/machines/mpc8315e-rdb/

The system randomly hang when running commands either on NFS or on hard disk.
The oeqa automation test and LTP/Posix test can not finish due to this issue.

The issue was introduce since the kernel was updated to 5.2.

Zhe He (zhe.he@windriver.com) narrowed it down to the following kernel commit which was merged in 5.1-rc1:

commit f8b58c64eaef03946dbb1b100ba0255f72031c17
Author: Christophe Leroy <christophe.leroy@c-s.fr>
Date:   Thu Feb 21 10:38:00 2019 +0000

    powerpc/603: let's handle PAGE_DIRTY directly
    
    PAGE_DIRTY corresponds to the C bit. If writing on
    a page for which the C bit is not set, a DataStoreTLBMiss
    is generated. No need to check it in DataLoadTLBMiss.
    
    Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

He has backported a patch from upstream and sent it to the list: https://lists.yoctoproject.org/pipermail/linux-yocto/2019-September/007995.html
Comment 1 He Zhe 2019-09-26 02:14:35 UTC 
I have sent the fix to linux-yocto.

The maintainer would rather sync up with upstream stable later than merge the fix right now. So we have to wait until the patch goes to stable tree and is merged back.

https://lists.yoctoproject.org/pipermail/linux-yocto/2019-September/007999.html
Comment 2 Bruce Ashfield 2019-09-26 15:24:17 UTC 
I actually did merge this one. It is in my recent v5.2 SRCREV bumps.
Comment 4 Yi Zhao 2019-10-15 01:55:32 UTC 
Verified with 3.0 RC2. Git rev: master/94f6b31befda5c496f65e863a6f8152b42d7ebf0