• Sergey Senozhatsky's avatar
    of/unittest: fix infinite loop in of_unittest_destroy_tracked_overlays() · 815d74b3
    Sergey Senozhatsky authored
    of_overlay_destroy() can return `-ENODEV' error code once it
    failed to find the requested overlay in `ov_idr'. However,
    of_unittest_destroy_tracked_overlays() does not handle this
    error code correctly and continues to call of_overlay_destroy()
    on the 'missing' overlay over and over again. This results in
    a printk flood
    
    [..]
    [   33.497583] of_overlay_destroy: Could not find overlay #6
    [   33.497583] of_overlay_destroy: Could not find overlay #6
    [   33.497584] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6
    [   33.497584] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6
    [   33.497586] of_overlay_destroy: Could not find overlay #6
    [   33.497586] of_overlay_destroy: Could not find overlay #6
    [   33.497587] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6
    [   33.497587] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6
    [..]
    
    which is not really good due to printk design, and can lead to soft
    lockups, hard lockups, etc. (depending on the context console_unlock()
    is being called from). The problem has bee observed in real life
    and reported by Ying Huang.
    
    This patch does not address the root cause of missing overlay in
    `ov_idr', it fixes the endless loop only.
    Signed-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
    Reported-by: default avatarkernel test robot <ying.huang@linux.intel.com>
    Link: lkml.kernel.org/r/87fuwk1c0o.fsf@yhuang-dev.intel.com
    Signed-off-by: default avatarRob Herring <robh@kernel.org>
    815d74b3
unittest.c 52.2 KB