• Tingwei Zhang's avatar
    coresight: cti: disclaim device only when it's claimed · 0dee2826
    Tingwei Zhang authored
    Coresight_claim_device() is called in cti_starting_cpu() only
    when CTI is enabled while coresight_disclaim_device() is called
    uncontionally in cti_dying_cpu(). This triggered below WARNING.
    Only call disclaim device when CTI device is enabled to fix it.
    
    [   75.989643] WARNING: CPU: 1 PID: 14 at
    kernel/drivers/hwtracing/coresight/coresight.c:209
    coresight_disclaim_device_unlocked+0x10/0x24
    [   75.989697] CPU: 1 PID: 14 Comm: migration/1 Not tainted
    5.9.0-rc1-gff1304be0a05-dirty #21
    [   75.989709] Hardware name: Thundercomm Dragonboard 845c (DT)
    [   75.989737] pstate: 80c00085 (Nzcv daIf +PAN +UAO BTYPE=--)
    [   75.989758] pc : coresight_disclaim_device_unlocked+0x10/0x24
    [   75.989775] lr : coresight_disclaim_device+0x24/0x38
    [   75.989783] sp : ffff800011cd3c90
    .
    [   75.990018] Call trace:
    [   75.990041]  coresight_disclaim_device_unlocked+0x10/0x24
    [   75.990066]  cti_dying_cpu+0x34/0x4c
    [   75.990101]  cpuhp_invoke_callback+0x84/0x1e0
    [   75.990121]  take_cpu_down+0x90/0xe0
    [   75.990154]  multi_cpu_stop+0x134/0x160
    [   75.990171]  cpu_stopper_thread+0xb0/0x13c
    [   75.990196]  smpboot_thread_fn+0x1c4/0x270
    [   75.990222]  kthread+0x128/0x154
    [   75.990251]  ret_from_fork+0x10/0x18
    
    Fixes: e9b88058 ("coresight: cti: Add CPU Hotplug handling to CTI driver")
    Reviewed-by: default avatarMike Leach <mike.leach@linaro.org>
    Signed-off-by: default avatarTingwei Zhang <tingwei@codeaurora.org>
    Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
    Link: https://lore.kernel.org/r/20200916191737.4001561-6-mathieu.poirier@linaro.orgSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    0dee2826
coresight-cti.c 24.3 KB