On Mon, Oct 18, 2021 at 10:07 PM <meng...@windriver.com> wrote:
>
> From: Meng Li <meng...@windriver.com>
>
> In orininal code, use 2 function spin_lock() and local_irq_save() to
> protect the critical zone. But when enable the kernel debug config,
> there are below inconsistent lock state detected.
> ================================
> WARNING: inconsistent lock state
> 5.10.63-yocto-standard #1 Not tainted
> --------------------------------
> inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
> lock_torture_wr/226 [HC0[0]:SC1[5]:HE1:SE0] takes:
> ffff002005b2dd80 (&p->access_spinlock){+.?.}-{3:3}, at:
> qbman_swp_enqueue_multiple_mem_back+0x44/0x270
> {SOFTIRQ-ON-W} state was registered at:
> lock_acquire.part.0+0xf8/0x250
> lock_acquire+0x68/0x84
> _raw_spin_lock+0x68/0x90
> qbman_swp_enqueue_multiple_mem_back+0x44/0x270
> ......
> cryptomgr_test+0x38/0x60
> kthread+0x158/0x164
> ret_from_fork+0x10/0x38
> irq event stamp: 4498
> hardirqs last enabled at (4498): [<ffff800010fcf980>]
> _raw_spin_unlock_irqrestore+0x90/0xb0
> hardirqs last disabled at (4497): [<ffff800010fcffc4>]
> _raw_spin_lock_irqsave+0xd4/0xe0
> softirqs last enabled at (4458): [<ffff8000100108c4>]
> __do_softirq+0x674/0x724
> softirqs last disabled at (4465): [<ffff80001005b2a4>]
> __irq_exit_rcu+0x190/0x19c
>
> other info that might help us debug this:
> Possible unsafe locking scenario:
> CPU0
> ----
> lock(&p->access_spinlock);
> <Interrupt>
> lock(&p->access_spinlock);
> *** DEADLOCK ***
>
> So, in order to avoid deadlock, use the whole functinos
s/functinos/functions/
> spin_lock_irqsave/spin_unlock_irqrestore() to protect critical zone.
>
> Fixes: 3b2abda7d28c ("soc: fsl: dpio: Replace QMAN array mode with ring mode
> enqueue")
> Cc: sta...@vger.kernel.org
> Signed-off-by: Meng Li <meng...@windriver.com>
Applied for fix. Thanks.
> ---
> drivers/soc/fsl/dpio/qbman-portal.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/soc/fsl/dpio/qbman-portal.c
> b/drivers/soc/fsl/dpio/qbman-portal.c
> index 845e91416b58..a56dbe4de34f 100644
> --- a/drivers/soc/fsl/dpio/qbman-portal.c
> +++ b/drivers/soc/fsl/dpio/qbman-portal.c
> @@ -785,8 +785,7 @@ int qbman_swp_enqueue_multiple_mem_back(struct qbman_swp
> *s,
> int i, num_enqueued = 0;
> unsigned long irq_flags;
>
> - spin_lock(&s->access_spinlock);
> - local_irq_save(irq_flags);
> + spin_lock_irqsave(&s->access_spinlock, irq_flags);
>
> half_mask = (s->eqcr.pi_ci_mask>>1);
> full_mask = s->eqcr.pi_ci_mask;
> @@ -797,8 +796,7 @@ int qbman_swp_enqueue_multiple_mem_back(struct qbman_swp
> *s,
> s->eqcr.available = qm_cyc_diff(s->eqcr.pi_ring_size,
> eqcr_ci, s->eqcr.ci);
> if (!s->eqcr.available) {
> - local_irq_restore(irq_flags);
> - spin_unlock(&s->access_spinlock);
> + spin_unlock_irqrestore(&s->access_spinlock,
> irq_flags);
> return 0;
> }
> }
> @@ -837,8 +835,7 @@ int qbman_swp_enqueue_multiple_mem_back(struct qbman_swp
> *s,
> dma_wmb();
> qbman_write_register(s, QBMAN_CINH_SWP_EQCR_PI,
> (QB_RT_BIT)|(s->eqcr.pi)|s->eqcr.pi_vb);
> - local_irq_restore(irq_flags);
> - spin_unlock(&s->access_spinlock);
> + spin_unlock_irqrestore(&s->access_spinlock, irq_flags);
>
> return num_enqueued;
> }
> --
> 2.17.1
>
