• Alice Chao's avatar
    scsi: ufs: core: mcq: Fix &hwq->cq_lock deadlock issue · 948afc69
    Alice Chao authored
    When ufshcd_err_handler() is executed, CQ event interrupt can enter waiting
    for the same lock. This can happen in ufshcd_handle_mcq_cq_events() and
    also in ufs_mtk_mcq_intr(). The following warning message will be generated
    when &hwq->cq_lock is used in IRQ context with IRQ enabled. Use
    ufshcd_mcq_poll_cqe_lock() with spin_lock_irqsave instead of spin_lock to
    resolve the deadlock issue.
    
    [name:lockdep&]WARNING: inconsistent lock state
    [name:lockdep&]--------------------------------
    [name:lockdep&]inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
    [name:lockdep&]kworker/u16:4/260 [HC0[0]:SC0[0]:HE1:SE1] takes:
      ffffff8028444600 (&hwq->cq_lock){?.-.}-{2:2}, at:
    ufshcd_mcq_poll_cqe_lock+0x30/0xe0
    [name:lockdep&]{IN-HARDIRQ-W} state was registered at:
      lock_acquire+0x17c/0x33c
      _raw_spin_lock+0x5c/0x7c
      ufshcd_mcq_poll_cqe_lock+0x30/0xe0
      ufs_mtk_mcq_intr+0x60/0x1bc [ufs_mediatek_mod]
      __handle_irq_event_percpu+0x140/0x3ec
      handle_irq_event+0x50/0xd8
      handle_fasteoi_irq+0x148/0x2b0
      generic_handle_domain_irq+0x4c/0x6c
      gic_handle_irq+0x58/0x134
      call_on_irq_stack+0x40/0x74
      do_interrupt_handler+0x84/0xe4
      el1_interrupt+0x3c/0x78
    <snip>
    
    Possible unsafe locking scenario:
           CPU0
           ----
      lock(&hwq->cq_lock);
      <Interrupt>
        lock(&hwq->cq_lock);
      *** DEADLOCK ***
    2 locks held by kworker/u16:4/260:
    
    [name:lockdep&]
     stack backtrace:
    CPU: 7 PID: 260 Comm: kworker/u16:4 Tainted: G S      W  OE
    6.1.17-mainline-android14-2-g277223301adb #1
    Workqueue: ufs_eh_wq_0 ufshcd_err_handler
    
     Call trace:
      dump_backtrace+0x10c/0x160
      show_stack+0x20/0x30
      dump_stack_lvl+0x98/0xd8
      dump_stack+0x20/0x60
      print_usage_bug+0x584/0x76c
      mark_lock_irq+0x488/0x510
      mark_lock+0x1ec/0x25c
      __lock_acquire+0x4d8/0xffc
      lock_acquire+0x17c/0x33c
      _raw_spin_lock+0x5c/0x7c
      ufshcd_mcq_poll_cqe_lock+0x30/0xe0
      ufshcd_poll+0x68/0x1b0
      ufshcd_transfer_req_compl+0x9c/0xc8
      ufshcd_err_handler+0x3bc/0xea0
      process_one_work+0x2f4/0x7e8
      worker_thread+0x234/0x450
      kthread+0x110/0x134
      ret_from_fork+0x10/0x20
    
    Fixes: ed975065 ("scsi: ufs: core: mcq: Add completion support in poll")
    Reviewed-by: default avatarCan Guo <quic_cang@quicinc.com>
    Reviewed-by: default avatarStanley Chu <stanley.chu@mediatek.com>
    Signed-off-by: default avatarAlice Chao <alice.chao@mediatek.com>
    Link: https://lore.kernel.org/r/20230424080400.8955-1-alice.chao@mediatek.comReviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
    Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
    Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
    948afc69
ufs-mcq.c 12 KB